I must admit you are the only one I have ever heard say that Vista was "rock solid" Snow.
I must admit, I have never heard of anyone that thought Vista was good. I would almost go as far as to say that my worldview has difficulty accomodating someone that says that Vista is good.
Windows 8 is a different matter entirely.
Vista had a really annoying UAC setup, which I can understand because Microsoft has always had OSs that people love to write viruses for and stuff and UAC goes a long way to preventing things like that. Even though every OS is basically just as vulnerable to attack, Microsoft always got the most flak by way of having the most market share in the OS department. Vista did a lot to combat that, way more than any other OS, but they went kinda too far in the other direction.
Windows 7 was basically the same thing as Vista with some small enhancements here and there and making the UAC way less annoying.
Windows 8 is kinda just like Windows 7 except that it took away the start menu and added tiles instead, a change which turns a lot of people off but is just fine for everyone else. No real bugs or complaints other than that. Seems to be really good in general and most problems come from 3rd party drivers and programs that aren't coded right.
Really, most problems with Windows were always 3rd party stuff not coded right, but Microsoft has just been trying to find ways to deal with that without having the problems crash the whole PC. They have been doing really good with that, especially in Windows 8. Now a lot of times the OS will segregate a program and if it crashes then it will only kill that little segregated part of the OS and not affect anything else. We aren't all the way there, but MSFT has made a lot of progress.
The biggest thing that MSFT has to deal with is that they want to institute change very rapidly and users don't want to experience change that rapidly. MSFT is underestimating how much people are attached to the old stuff they are used to using.
If it were possible to just force everybody in the world to use Windows 8 and they didn't have an option to stick with the old stuff, then everybody would have gotten over the differences pretty quickly, but instead what you have is companies like Stardock cashing in on the huge number of people who want their old stuff back.
I am not even really against that so much, but I do think everybody would be better off if the entire planet upgraded to Windows 8 and people just installed Start8 if it was really such a big deal to them. The old OSs really have very little value atm and MSFT could do a lot of more productive things with the resources it is using to support the old OSs.
The 'Metro' way to do things is utter crap. Anyone who thinks otherwise is simply deluded and blindly following MS's [mis]direction.
A decade or so of Windows evolution was logical. Profound change just for the sake of change is commercial suicide. MS thoroughly understands that - NOW,
Back in reality, dismissing an opponent's argument out of hand is such a bad debate tactic as to make sure you aren't taken seriously by anyone.
Also in reality, MSFT was making pretty large changes the whole time and had pretty good reasons for most of them. They weren't actually changing things just so they can say it was changed. The things they changed were (at least in their mind) improvements.
We can sit here and argue about whether Person A really wants their PC and their Tablet to have the same exact UI and we might come to different conclusions, but MSFT's stance is that they can spend more time/effort on new functionality if they have to support fewer numbers of OSs.
They could have also tried to just make Windows 8 look like the UI that comes standard on stuff like iPads and Android phones where you can gesture to move sideways to additional screens or whatever, but I am not sure I would like that more. In fact, I wish my Andriod phone didn't have any screens I could get to by gesturing sideways from the home screen. I either want to be on the home screen or I want to go into my app list, and those screens that show up when I gesture sideways annoy me.
Anyway, I think I would prefer the way that the Metro UI works now as compared to having my Android OS on my PC. It would kinda be interesting to see what Android would look like on my PC, but I think I would go back to Windows 8 after trying it out and I kinda wish I had Windows 8 on my phone actually.