The Knockoff Debate  

Rikki -- I agree with some...
Rikki -- I agree with some of the others; don't pander too much to your home when outfitting it. It always looks stagey.
As for repros, I think the appeal lay in the concept and philosophy that was behind most of the 20th century designs you refer to. Original examples are more like benchmarks or reference pieces. Modern reproductions are more practical, in many instances, as there is a dividing line between patina and detritus, especially with upholstered pieces. To my eye, a Knoll sofa always looks like a Knoll sofa, whether it be from 1967 or 2007.
...by the way, Florence Knoll is still alive, so any modern day manufactured piece is technically contemporaneous to one created in the beginning.

Whitespike
I'm afraid if I say I'm not badgering you it will be contradictory ;-D I promise, it's not personal - we just seem to be coming up on different facets of the same arguments lately. And even here we dont really disagree, I just think the term 'quality' should have some qualifiers to it.
I like some of the stuff Plycraft produced -espcially their very quirky little known pieces. Most of what I've seen is fairly well constructed - but they also left a legacy of awful working conditions for their people, stole designs left & right, created an environmental disaster (the factory location is now a superfund site), and ended it all with a spectacular 6 alarm fire that consumed the entire factory and was suspiciously blamed on a homeless man.
Which isnt to say that George Mulhauser wasnt a good designer, or Cherner, or even some of Goldman's own works - although its hard to figure out a lot of the attribution short of digging through old patent files.