Yes 10.10 was released at least a year too early - it really should not be out of beta. I get daily "pizza wheels of death" with 10.10.3 on my Mac Pro. On the same machine I have yet to have Windows 8.1 crash. The hardware is fantastic, the software far less so.
btw did you do a fresh install? I'd always just upgraded and had no problems; until Yosemite. It's a bit more time consuming but Yosemite has worked great for me since I did a fresh install.
I did a semi-clean upgrade. I bought the Mac Pro late last year and it stil had 10.9 on it. I upgrade to 10.10 before copying across my user files and software from my laptop running 10.9. I have been trying to figure out what the cause is by looking at the crash logs without any success. I do find that daily reboots lessens the risk, other than this there does not seem to be any rhyme or reason.
I have been using MacOS of various stripes since 1990 (I am a biologist by background and biologists were one of the few groups that stuck with macs through the late 90s). Other than 10.1 Yosemite is the buggiest OS 10 release to date in my experience.
Interesting, I was in the same upgrade boat, but went back to 10.8 on my Mid-2011 MBAir. With only 4GB of ram, 10.10 was killing me, constantly spooling up the i7 & fan to screaming levels.
