Marko, nice enough survey, but... it does not cover my ongoing experience with OSes: in fact I still do use all three of them.
On an older Pentium4 (1.8 MHz) PC I'm still under XP SP3 which works (fairly) correctly. So I'll stick with it even after they stop support (and if that proves a problem, Ubuntu it will be!)
My main (HP) machine came with Vista cause I was naive enough to believe that buying a Vista machine straightaway would be "the" solution (never performed an MS "upgrade" as from DOS 2.1, cause I don't trust “them”: always performed a full format + clean install!). Wrong I was: 4 complete reinstalls in about 2½ years! And still (always after a short period of "good" behavior) unstable, prone to blue-screens and crashing my faithful Office XP a few times a day! A new "experience" for this old (71
) guy, active for 25 years in the PC support area (even started the IT Helpdesk of a 3000+ Telecom company...). Well that doesn't help me a single bit (well, almost), with this Vista cookie monster. Not that I am a Vista basher as such: I thought the problems reported everywhere were due to inadequate hardware or not so successful upgrades! But here I'm merely reporting my findings.
My new (HP) portable runs Windows 7 and does it well (so far
.) If it weren't for my 26" screen on the desktop and a dictionary I can't do without (not recognized under Win 7, whatever "solution" I applied), I would completely switch to the portable with an external mouse! Only problem after 2 months: I had to do away with the automatic Windows updates, because after an SP1 update the system would install the same new updates again and again, each time I started the machine. So far Win 7seems even stabler than good ol' XP! And that's something. On the hardware level my desktop and portable run almost equal in the benchmarks, but Win 7 indeed makes the portable run much faster (not only in boot and shutdown times, but over all. So far still no BSOD nor wacky behavior and since the curtailed Office version it now carries is more than sufficient for my needs (I miss the dictionary though), even if this old guy is not very banner-minded, I'm not going to risk making my life unpleasant on that by trying to install Office XP...