On 2nd thought Vitra  

This seems to come up
This debate seems to come up about once a year or so on various design blogs. It's fun because I can see both sides of the issue, and I do love playing the Devil's Advocate.
First off - yes, White Furniture is a joke - they sell cheap Chinese crap that has the outer layer of design icons. However, Vitra and Modernica are harder arguments to rail against.
First, Vitra: The Vitra design museum owns one of the largest collections of Eames artifacts in the world. They also provide a valuable service by keeping interest in design alive, and have legitimately been the European manufacturer for many Herman Miller products since 1957 (only a year after the release of the Eames 670). Much of what we might see as an arbitrary change of materials comes from other factors. The Vitra versions of the Eames plastic chairs, for instance, are now injected molded plastic. According to Modern Classic, by Daniel Ostroff, the decision to change the materials came out of concerns about the environment impact of fiberglass. The fiberglass chairs are not recyclable, nor do they decompose in landfills. It's unclear why Herman Miller stopped production of them, but Vitra's website seems pretty clear about their desire to lessen their environmental footprint. A purist of materials would say that this is against the original design, but you also have to look at the spirit in which the original object was created. Then the argument comes down to whether the Eames would have persisted in using fiberglass out of habit, or would have - as they had done with all of their other furniture - modified and changed and created new iterations based on updated materials.
EDITED: 11/26/08
I have changed my opinion on Modernica. Modernica has shifted their product line away from their nicely designed original pieces into more and more clear copies (knock-offs). In addition they are aggressively promoting themselves as the 'authentic' manufacturers of the shell chairs - something that is just not true.

What it boils down to...
I think what it boils down to is a desire for a lot of us design addicts to stay in a static moment. But nothing in life is static, things are always evolving and changing. If you want an original - buy an original, but don't expect a modern production to be the same.

I have the vitra eames rocking chair
and it's made of glorious plastic and I love it. And it looks a lot better (and cost a lot less) than the cruddy originals you can buy in second hand auctions, with their filthy chipped and cracked shells. Plus I'm not scared about using my chair because it's not some museum piece(I feed my baby in it every night...in fact they were originally given out as gifts to Herman Miller employees as nursing chairs)No way would the Eames's have persisted with fibreglass if they were alive today. They were MODERNISTS. That means they used the most MODERN materials and technology to solve a problem. Plus the environment wasn't even discussed in the 1950s.

lucifersum
Lucifesum very well said . I could not agree more with what you said and how well you said it, I was saying that I was just disapointed to see how the Icon of Icons was reduced to a injection molded chair that you could buy on the front garden part of K-Mart , Yes we true fans do love our say when it comes to really saying some thing about design . . the world is changing and has for a long time the buzz word for this year is GREEN, GREEN, can't pick up a magazine with out Green Green even before Al Gore took credit for it , The eames were designers not G-ds . and what they would have done to see us through the next part of the 21 century would be interesting. I just hate to see great great ideas reduced to injection molded . whats next the 670 and 671 in a nice light blue injection mold cause it is good for the enviorment.. They tried in 89 to say good buy to the rosewood . and I guess Herman miller has been somewhat succesful?? but looks what creeps up for the 50 th anniversity of the eames chair a Sandos palanster . a form of rosewood. ( really they could have introduced this the year after they got rid of the rosewood They just did not want to.

One word for you young man, PLASTICS.
LRF - Injection moulded plastic isnt as bad as you're making it out to be. Don't forget that when they began the production of the shells in 1950 fiberglass was a fairly foreign material to most people. It was also a radical break away from the Eame's earlier preferred material: plywood. The fact that the shells weren't created in polypropelene until after the Eames' deaths doesnt mean that they wouldnt approve.
Take for example the plywood and metal dining chair of 1946: http://www.architonic.com/4100683
Now look to the "secretarial chair" produced in 1971, while the Eames were still alive:
Here you have the same idea, same shape, same frame, but the seats have changed from plywood and shockmounts to upholstered injection moulded plastic with integrated attachments. Thats a drastic change of materials - very far from the original plywood pieces, and with a very different feel - yet completely Eamesian in design.

Also-
Also - I think you should do some research into the variations of Rosewood. It's my understanding that the original rosewood veneers were made from brazillian rosewood, a species very much endagered. The Santos Palisander is a different species of wood that is renewable.

LuciferSum
You own this. You are so right.
My only issue with the Vitra shells is not the material or lack of shockmounts. As Lucifer explained, this technique has already been done while the Eameses were alive. What I don't understand about the reproductions is the severely disfigured eiffel base. Can someone explain this change to me? I wonder if is a European safety regualtion, much like the U.S. requiring Herman Miller to change the aluminum group series to have 5 star bases rather than 4. I don't get either. People have been using both for years and years. I have never fallen out of one and hurt myself!
Also - on both the Vitra and Modernica front, I wish the runners on the rocking bases were shaped more like the original. But that isn't a deal breaker. I couldn't look at that squatty eiffel base every day!

Vitra Buckets
You all know what the effiel bases look like cause you are all interested in design and have seen the real Eames effiels for years The average Joe that buys a Eames Bucket chair from DWR . They Just really want the look they don't care about the squatty base cause that means nothing to them . They just feel that it is the time to get some cool mid-century modern piece
That will look good in there apartment or flat, Just keep them away from White on White were those folks make stuff up as they see fit.

New Vitra "H" base is also smaller.
I have an extra newer chrome Vitra H base and it's not even close to the same depth as a original Herman Miller. I was always looking twice at it and it didn't click until I had them side to side.

reply to H base
Now that is really different . So many times, companies that make reproductions will make the product smaller or larger not to violate the trade dress laws here in America . But Vitra who has a long standing relationship with the Eames Estate would not have to worry about that since they hold all kinds of agreements with them
. I had 8 knoll Brunos from the 60's that I was using for a conference room and I needed 2 more I went out to ebay and bought two more chairs knowing that they were not Knoll , but since i was recovering them all in matching leather I said NO BIG DEAL I was wrong ... after recovering them in matching leather that was far from cheap and installing them for the clinet in there wonderful new conference center.
Need I say I made a big mistake .. they were almost 2 inchs smaller in the back seat . Every thing looked the same but when they were installed next to the original Knolls they looked awful .
Of course, we found 2 more Knolls and used the other 2 in a executive office( I am sure he was thrilled!!!!!)
i was not out any money , but when you think about the H base from Vitra being smaller you start to wonder Why??? ....They can't say a ergonomic,enviroment,green
problem, cause it is just a base not fiberglass.

I think there have always been
I think there have always been differences between the Eames designs of Vitra furniture in Europe and Herman Miller in America. About a year ago someone posted a flickr page showing the differences between the Vitra and HM LCW. And the vintage Vitra versions (say that 3 times fast) of the fiberglass chairs are a different shape as well.
It doesnt make a lot of sense why the actual design would be changed for each market, so I'm guessing perhaps it is due to the machinery or regulations in those countries. A similar example: Mazda released the RX7 as a two seater in the states, but in Japan there is a high tax on two seater cars. Mazda's solution was to stick two (utterly useless) little seats behind the driver/passenger seats, and thus open up the market without the high tax.
Perhaps there is a safety regulation or such. I cant find anything on Vitra's website about it, but it does appear that the Eiffel base for the arm chair is a few inches longer front to back, and that the mounts might be narrower where it meets the chair.
http://www.flickr.com/photos/delabassee/242476419/in/set-72157594282747558/

Lucifer, I agree...
Lucifer, I agree wholeheartedly with your statements on Modernica in your edit of your first reply. The arrogance of Modernica these days is repulsive. I own and have owned a few pieces of Modernica version Eames and George Nelson. Neither their crafsmanship nor their attention to detail are impressive. And once you sit back and think about the fact that they have no paperwork from the old Herman Miller faction endorsing them(save the Bubble lamps), you realize that they are nothing more than petty salesman. A money grab, nothing more. They take a half assed approach to reproducing classics and sell them for more than twice what any other 'knock off' company charges. The only reason they've gotten away with it to this point is the quality of materials in their 'catalogue'. But at the end of the day, if you buy a piece from them you're buying a knockoff.

'I have the vitra eames...
'I have the vitra eames rocking chair
and it's made of glorious plastic and I love it. And it looks a lot better (and cost a lot less) than the cruddy originals you can buy in second hand auctions, with their filthy chipped and cracked shells'
Stephen, I am afraid I don't agree with that. I have a gorgeous Zenith chair, I am a little scared to use it much I admit, but the thick fibres just make this chair what it is. Without the fibres, the chair loses soul in my opinion.
I own lots of Vitra and Miller furniture, I *usually* prefer Vitra's offerings, but in the case of the RAR chair Miller wins hands down.

I have a Zenith chair and...
I have a Zenith chair and i never sit in it. I am afraid it might crater it is so old. also I will go on the record, nothing is better than the Modernica bubble lamps, they are the best!, every bit as good as the Howard miller lamps of the 50's and 60's and i will bet they will last a lot longer.
I am not that wild about the Modernica bucket chairs, cause I always love the originals but I think it is great that you can find a fiberglass shell in 10 different colors from Modernica , It is far better than the 4 colors of solid plastic that you can get from Vitra.