I get this awful glitching when switching spaces and I can’t really see much of a speedup. Not sure about the awesomeness, but it is fairly easy to try out.

I have the same problem, switching spaces will get stuck or glitch. Often times skipping the space i was trying to get to. didnt have this problem on mavericks. I wiped my system and reinstalled and its still there. Im not sure what the point of yosemite is, considering all these phone features google supports via chrome plugins why apple has to bake it into the OS perplexes me.

If you have my problem (bad perf running Yosemite on software rendering), it's far better than using Quartz Debug to disable Beam Sync. Pure curiosity: what's your computer?