This isn't the first time that things have gone wrong with a new version of OS X. The shift from 10.6.8 to 10.7 was an absolute catastrophe from both a performance and a stability basis. 10.8/ML was slightly better, and, I've stayed on 10.8.5 waiting for 10.9/Mavericks to stabilize.
From colleagues who use it, and the various KEXTs that I also have, it looks like Mavericks, and KEXT support for it, actually hit a pretty good stability plateau around June/July of this year - so I"m looking forward to upgrading to it sometime early in the next year.
There is zero chance that I'm going to be considering 10.10/Yosemite as my production platform (if at all) any earlier than 2016. I'm always slightly bemused at how quickly people feel the need to rush into the next operating system. Was the older one really all that bad? About the only thing I'm missing right now is Omnifocus doesn't support 10.8 (10.9 or newer). Other than that, I can live with the various warts on 10.8.5 (particularly now that FTDI drivers don't kernel panic my system every time I pull out the USB cable) - Kernel Panics are now a biweekly (instead of every couple days)event, and my only real need to reboot the system is when my USB devices aren't recognized (usually after a sleep) - but a 3 minute reboot and everything is fine again.
Still - I think it's good to call Apple on their crap - 10.6 was actually a pretty decent release, and I don't think they've managed to get one that good out since then.