Been using Windows 7 for a couple of weeks now, and I must say this is MS' best effort yet. Very smooth and fast. Boot up and shut down times are down to less than a minute even with AV and sundry programs and all or almost all software that I am wont to use run perfectly on it, even some of Win XP vintage. Haven't used the libraries much yet but the search functionality is well implemented and it gives you more features than previous iterations. The Aeropeek and similar addons to the GUI are thoughtful and work really well. I find myself using them all the time since I have multiple windows open quite frequently. The floating gadgets are also a much better option than Vista's sidebar. But the one thing that I always marvel at is the speed of the system. Having gotten used to yawn inducing boot-up times from the XP days, I love the fact that I switch on my desktop as soon as I reach home and it's up and running by the time I take my boots off. In contrast my laptop running Vista takes almost 4 minutes to bootup. Of course it's an aging machine so there's no comparison but still it pleases me!
Compatibility issues are also handled more efficiently now and you have to option to go online to search for drivers/solutions. UAC is less obtrusive, thankfully! All in all, it's a nice bit of software and works quite well.
I've read that Win7 is what Vista was meant to be. Many features that you find in Win7 were originally planned for Vista but time constraints and an ever-increasing gap since WinXP came out caused its premature release. Maybe that's true and if so, it speaks volumes for MS' unconcern for its customers, saddling their customers with a half-baked product and forcing them to upgrade further within a couple of years. But I never really found Vista hamstrung in any way. People have complained to me day in and day out about how it's not smooth, that there are compatibility issues and it's not stable and what not. Mostly I hear that it's just not good enough. Of course when I have asked for what specific problems these people have faced with Vista I get non-committal grunts, and half explanations about how they've heard bad things about Vista. The one problem I did find was Vista's incompatibility with SQL server and many commercial apps (not too sure which, but those were the only concrete answers I got, from IT people in various sectors). But for the average homeuser, I don't know what the brouhaha is all about. It was a fine piece of software and worked well. Of course, Win7 works better but Vista was an improvement over XP too. So it is with every new version of any software. Vista was just a victim of bad publicity more than anything else in my view.
Not that I am a fan of MS in any sense of the word. I have read what they/ve donein the past with Netscape and what they tried to do with other SW manufacturers with XPs launch (I remember they weren't allowing any non MS service icon on the desktop) and how they've coerced PC makers to exclude various software programs from their OEM set. But with all the calumny poured upon them and rightly so, they still had come out with a good piece of programming with Vista and they still got pasted!