I see the same question for every version of every operating system (and app) that's ever been released, and the same spectrum of responses. When it comes down to it, either you are the kind who likes to update early, or the kind who likes the stability of the tried-and-true. What we say here won't change that.
But a guy's gotta try!
Judging simply by posting activity (which is always dominated by those who have had problems), Yosemite is as good as or better than most. There is no "Yosemite-gate" that would warrant greater than average caution. My own experience, on three different Macs (including a 2008 iMac running on 5 GB RAM), has been great, but that's only three data points, not a valid statistical sample.
Back when I was doing corporate IT (that was in the 90s, fwiw), my attitude about MS-DOS and Windows updates was, "Every update I've installed improved my productivity enough to justify the cost." Granted, that had everything to do with my productivity, but there were always several new features on the user end that could justify the cost as well, so long as the users knew to take advantage of them. Though my focus has shifted from Microsoft to Apple, the basic premise still holds true, and with the advent of free OS X updates, the cost-benefit curve has gone through the roof.
And new features may be the crux of it. If your current OS does everything you ask of it, and you have no interest in the new features, then there's no compelling short-term reason to change. Long term, however... If you skip a few generations of any OS (or app), you'll be hit with learning curve issues - the cumulative changes may be many, your ability to assimilate (and benefit by) them all may be less than had you made the change gradually.
My wife (who is very computer literate, fwiw), has always preferred to delay, and when change finally comes, it's often forced upon her, typically by aging/over-taxed hardware. The updates tend to be traumatic and frustrating - instead of facing one or two challenges per update, the list is usually much larger.
So long as you have no critical apps that can't run on it (the list is pretty short, if you're running Mavericks), so long as your hardware is capable (and I've seen few, if any, reports that Yosemite runs poorly on a system that can run Mavericks well)... I see no reason to avoid Yosemite at this point. Wait for 10.10.2 if you wish - an extra level of debugging can't hurt, and you won't have long to wait.
For me, SMS forwarding alone is worth it - Messages on my iPhone, iPad, and Macs are finally all in sync - no more "If he/she is using SMS, I need my phone." Plus, no matter what keyboard I use on my iPhone, touch-typing on my Mac (when I can) is far faster. It's geeky fun to answer and place phone calls from my Mac, though hardly essential. iCloud Drive brings iCloud to Finder, which can be a very good thing. Overall iOS/OS X integration is tighter, which makes me happy (though there are still some setup "gotchas" that could be better addressed in documentation). If you're not as committed to The Ecosystem, less of this will matter.
I am also thinking of installing it on my iMac 2012
