no one?...except me
According to Vitra's website the fiberglass chairs went out of commission in 1993 for environmental reasons. Production was restarted using injection molded polypropelene for the seating. In changing materials Vitra changed the design slightly as well.
Instead of rubber shockmounts the chairs now have a built in nipple to which the bases can be screwed. I am sure this change has meant more efficient production times for the chair, and on the user end - less damage to the chairs because of shockmount failure.
The surface and flexibility of the chair have also been affected by the change- polypropelene has a surface that is slightly textured. It has almost no shine, and (in my opinion) gets dirty very quickly.
The fiberglass chairs flex slightly in the back - I find the poly chairs to flex even further. I also believe Vitra made some changes to the bases - altho I dont know enough about that to comment.
In personal opinion I like the fiberglass chairs better. The plastic ones may be lighter - but there is a luminosity I find lacking. The only thing I can think would be better in the plastic chairs is a quicker acclimation of the material to the temperature of my buttocks. LOL. As anyone with a fiberglass chair knows - the material does not change temperature rapidly - making for a brisk seat in winter months. lol.
If you need any help, please contact us at – info@designaddict.com