I must admit that I've had several good years after switching to Apple, but the last year and a half has taught me never, ever to download a software update when it is first available. OS6 on the iPhone, the last Airport update, 10.7.5, and now iTunes11. It seems like they're all coming out with either outright errors (like maps and the Airport connectivity issues) or with the strangest taste in what consitutes a logical user experience.
In all of this, one has to be cautious about just reacting negatively to something new of course, but I am seeing a real degradation in things like search capability in Mail and Address Book, a whole new hyperactive spell checker on my iPhone that agressively completes words (incorrectly) much more often than previously and functionality in iTunes that takes more clicks to get to than previously (if it still exits at all).
One of the things that drove me away from Windows (besides the fundamental performance issues) was how MS would change interfaces with each update just for the sake of change. It seems like in the last 18 months Apple has started to do the same, like someone left the software department without adult supervision.
Still, I wouldn't go back to MS, but this short term trend of cranking out software without working out the functional and qualitative errors first is worrying.