I just bought a brand new MBP (Mid 2014) last week because my "old" macbook started experiencing GPU Panics.
My old macbook had the wifi connection issue after upgrade to Yosemite.
The first thing I experienced on this one was the GPU Reset about 10 minutes after I installed Yosemite.
I also have the impression it is a bunch slower than my old MBP, graphics are really sluggish. The graphics switching between integrated and discreet is sometimes visible as a small "flash". So basically I traded a macbook with wonky wifi and a hardware issue with the nvidia chip for a brand new one with nvidia crashes.
Been an extremely happy Apple user the last 4 years, but this Yosemite upgrade has really cost them a lot of reputation points in my book. It's so not their usual M.O.
My god what a bunch of crap this thing is. Hopefully a patch is released really soon, both for the wifi problems and the bad graphics performance.