I've had limited experience with it, when a friend who's not real computer savvy got a new PC, and she and I both found it too glitchy, to the point that she called Dell and raised hell (they basically talked her into going with Vista), and they wound up replacing her system with one with XP preloaded...
But my bias against it really goes back further than that, to the time I took their test to check my hardware compatibility... turns out that my scanner and my inkjet printer (but not my laser printer) would not work if I installed Vista...
Screw that, both those pieces of hardware were HP products, and not that old... there's no reason that Vista shouldn't have been able to recognize them...
Like I said, I'm generally all for getting the newest and the bestest, and if the next release is really going to be the improvement you say it is, I'd be willing to think about beta testing it, just because I trust your judgement on such matters...