Regarding stability issues, I've gotta say just based on personal experience that 75% of it is HARDWARE HARDWARE HARDWARE! When I get calls from friends and family regarding flaky PCs, invariably I crack the hood on the system to find generic, no-name RAM, substandard (non mil-spec??? ) motherboards by wonderful companys like MSI and so forth, mismatched RAM (PC2100 + PC1700 etc.) and all sorts of Frankenconfigurations.
This can often be the case yeah... But still it cant explain all problems.. I mean if it was just the hardwares fault, then home come it works perfectly on some other OS?
And you cant dismiss the fact that every user have a diffrent perception on what is stable/fast and so on.
I have heard many people saying how they can have their windows puter up for a whole week! Which i personally think is lousy! A decent os after my opinion should not need to be rebooted or crash in months of time. Take for example my dads pc running linux... It is at somewhere between 75-80 days now, and its being used every day... with winXP the exact same puter either crashed or had to be rebooted usually before a full week.. And yeah... was using ONLY microsoft certified drivers!
And btw why do you have to reboot windows still? Installing gfx drivers, soundcard drivers nearly allways leads to a forced reboot.. even in some cases installing a damn program... i really expect more from a modern OS.
I am not saying linux is even near perfect though, it has its flaws also... i think thought that beos was pretty damn near perfect, would have been an awesome OS if there had been more games/software and hw drivers.
And i again say... every OS has a flaw of some sort but some have more than others...