Every operating system goes through a few growing pains and has to be tweaked in it's early stages, especially those from Microsoft. People tend to forget the total chaos that occurred when Windows XP replaced Windows 98. The compatibility issues, the driver issus, etc. And half of those problems involved Microsoft products. But over time, with fixes, updates and service packs, it grew to be the XP we now know and love. Vista hasn't even come close to those types of problems and is now a sound, stable system. Manufacturers always have to update drivers for compatibility issues and between the new operating system and gaming manufacturers thirst to always provide bigger and better, there will always be issues, no matter what operating system.
Vista does have a large footprint, but doesn't even come close to the footprint gaming manufacturers put on a system. What has been the result of this large footprint? Computers that now come with 2 to 3 times the amount of ram and hard drive space to support the large footprint. Thus adding additional stability to the system. At rock bottom prices, I might add.
I also do this professionally and have done so since way back when you had to manually add programs to upper memory just to have enough resources to get a game to function. And what I've found while working on Vista systems is that most problems are a result of the user not having enough resources for the OS or have failed to update drivers. Battery issues and other stuff like that can be worked around and to me does not diminish the OS. Other issues are unique or specific to the hardware of the other manufacturer (and usually resolved with a driver update). And just like it's always been in the past, many of the issues are a function of user error, viruses, malware and the failure of the owner to open the manual and read before he does something or when a problem arises.
But, to end this debate (at least on my end), it always seems to goes back to perception. My laptop has crashed once in the the 18 months I've had it. I installed Fallout 3, started playing and I got kicked out. I updated my video card drivers and haven't had a problem since. I've worked on other Vista systems and most of the problems have been simple fixes. I haven't had to reformat a drive and reinstall the entire operating system yet. So my perception of Vista is a good one, but my perception comes with 25+ years of computer diagnostic & repair experience. Your perception is obviously different and is just as valid.