Well . . . I have Windows Vista x64. I built my PC in June of 2009 (Core i7, SSD, the whole 9) after having an AMD Athlon 64/64MB Onboard Video/80GB IDE HDD Type system for 5 years, which I hated. One week after I first installed my copy of Vista, the internet would not work. Absolutely nothing could connect to the internet, and there was no reason for it. When booted into Ubuntu, it worked fine. Microsoft said my OS was corrupted. Just before I was going to start all over with my OS, all removable storage devices refused to appear in 'My Computer' or diskmgmt.msc or anything of the sort. Again, they worked fine in Linux. So, I ended up reinstalling the OS and after a year, everything has worked completely fine except for a few times where a program would halt and then lock-up the whole PC at boot for no reason. No problems at all, really. I will say however, that I do get the occasional BSOD for no reason at all, but it will always reboot fine. Also, I really late the Ubuntu and Kubuntu interfaces. On the bad side, I MUST reboot at most every ~60 hours or so or else it will start glitching and just not running right. On the good side, I have over a terabyte of media and programs, as well as a ton of services and over 20 programs at startup, yet the thing hasn't glitched because of it and still starts very quickly.
So, my 2 cents, Windows (or at least Vista) is a bit glitchy and could use some work, but overall, I think it's way better than Linux or OSX mainly because of the interface and then also the power that you get with it. Windows CAN do way more than Linux or OSX will ever be able to do.
As for Windows 8, I think the App-Store idea sucks. I like it where all my software comes from different vendors and I'm in charge of the way everything happens with my software and updates. Also, I wanna see a more conventional windows, not the cheap, "One Size Fits All" crap where they try to fuse together a Tablet OS, a Netbook OS, and a High End Desktop OS with tons of intensive productivity. It just doesn't work, and I don't want to see Microsoft turn into Apple whether Apple is better or not.