I have a Weber 34/34 DGEV which I ordered from Quadratec and it seems to work fine, except I've had issues with the choke. I think it binds and sticks sometimes, and the spring can't always make it move the way it should. I also put a fuel pressure regulator on it and found out the recommended 3.5 psi setting was too low (it would stall and try to die out of stops when I'd just recently turned the engine on); turning it up to 5.5 psi fixed that.
If I had it to do over, I'd probably get the mc 2100 just because it's cheaper. The Weber North America guys were pretty nice about taking it back and trying to adjust the choke for free, but I got what I paid for and it really wasn't any better afterward.