Eames Lounge - new or used  

Vintage
The newer ones look too plastic.

Durability
A friend said that "the old ones are built better than the new ones"... is there any validity to this statement?

I think the vast majority of...
I think the vast majority of the people here will tell you to go vintage as long as it's in good condition. You mentioned that the leather on the ottoman was replaced; just make sure it matches well with the rest of the set.
It's been 58 years since its introduction, the Eames Lounge Chair has gone through many production changes with different materials, literally from the wood, leather, glides, even down to the screws and type of glue used. Most would argue the old stuff is better. To a large extent, I'd agree, especially about the construction of the chair. However, older chairs may require maintenance issues such as shock mount replacement and oiling the wood panels which isn't something everyone wants to have to deal with. If that's the case, a newer chair will probably give you better peace of mind.
Depending on where you are, you can probably find both vintage and newer pieces in the $3000-$3500. In fact, I think there's an ebay seller selling new walnut ones for $3500 including shipping. So if the figure you're talking about exceeds that, you may want to think about ebay. Either way good luck on your search!!!

I'd give newer ones the edge
as far as structural strength for no other reasons than the thicker panels and advanced glue/adhesive technology.
Older editions offer superior aesthetic value, but do very certainly come with all the associated caveats that kin mentions.
If your chair will really need to sustain heavy use, and things like patina and broken-in cushions are not high among your priorities, then new may be the way to go.
It's a personal call, in the end. In the meantime, I'd recommend trying to log some seat time in examples of both. These chairs don't fit everyone well.

VINTAGE FTW
If it's not a chair that you're going to be sitting in all day every day (like an office chair or a car seat) I wouldn't be too worried about the cushions wearing out.

By the way, walnut seems a bi...
By the way, walnut seems a bit boring to me personally. It'd be a tougher choice if it's a brand new Santos Palisander version. Also, when buying new, you just won't know what the wood veneer is going to look like until arrives at your door. So my vote is vintage.

Oh and the kid...
It actually will be sat in every day... and we're having a child very soon. It won't be all day/every day, but will be every day in the living room. Space is limited and the addition of the Eames would allow both my wife and I to lay out and get comfortable.
Hmmm... leaning towards new but still have a love for vintage!

Congrats on the upcoming arri...
Congrats on the upcoming arrival! We're in the same boat in fact. However, here's my wife's experience with the Eames Lounge Chair: she finds it hard to get in and out of the chair, especially with her ballooned tummy now. I bet it'll be even harder when she has our daughter in her arms. Of course, that'll all pass. Just something to think about.

to me
the vintage is way more sexy. The newer just looks...well, newer.

While I love Herman Miller as...
While I love Herman Miller as a company and love the idea of supporting their new products, I would absolutely not go with a new one if you are considering one or the other. If the chair you attached first is the vintage example, you picked a smart one. To me, it sounds like you are quite and very concerned about the chair wearing out.
Vintage Chair: If it has genuinely had the shock mounts replaced, you have a chair that is structurally as good as new. The wood is not going to rot. Instead, you will have gorgeous rosewood with a beautiful patina. It also looks like the chair you have is from the 80's, maybe 70's. This means that the cushions are filled with foam and fiberfill. It also means that the chair won't end up looking like the down filled chairs. The cushions will keep their shape and the leather will last another three centuries if you condition it every now and then. I've had many Eames lounges and ended up keeping one of my oldest chairs because I knew that as long as I kept my eyes open, I could use it as much as I wanted and keep it in beautiful/functional condition until it outlives me. If you have seen horrific Eames lounges, it is often because they were neglected. If the shocks fail in 50 years on the vintage one, you can replace them yourself or have Herman Miller due that it. If the leather starts to show a crack, condition it. Leather does not crack and decay unless it is neglected.
New Chair: They use great leathers now (not any better than before but better than the early 2000's) and the quality is still excellent. The new chairs, especially the walnut/cherry examples, just lack a certain something that only the old rosewood chairs have. You'll need to maintain both of them equally throughout the time you own it, so why not just get the old one?
The old chair looks as good as new anyways! the cushions look better than new and the ottoman matches beautifully. Keep a container of conditioner nearby to apply once every few months or year, take it apart and oil it every few years, and love it!
Just my two cents.

Thank you David R
This was very well put, DavidR. You've swung my opinion the other way (toward vintage). I'm fine with maintenance. Also, it's amazing to look at the oiled vs. lacquer finishes on the new chairs. The oiled are much more expensive but look much richer... and the vintage chair already has that going for it. And the saga continues. I will have a decision within a week.
Any other thoughts, specifically, how to get my wife on board with the vintage chair?

go new!!! I have both.
...
go new!!! I have both.
Vintage is for viewing. 50 year old chair has been completely restored and is a fine piece of artwork. I hate sitting in it as I am always afraid it will break. ( it did break once and took 3 months to repair perfect. New are more durable do not let anybody tell you different . I know what I am talking aobut as I am the proud owner of two of them. Do not let kids play on the chair as the arms will snap.

New or used
It happens that newly made classic furniture is not as good as the original product.
For example, if you look at a newly produced PK 22 chair, the original versions are better finished and the materials slightly better.
As long as it is in good condition, then a used example tends to have more character as well. As such when you come to sell it, it will maintain its price better, noinitial depreciation and people pay for "character".

Old is Best
A bit of history that comes along with any item is lovely, old and beautiful I say x