At the outset I'd like to make a quick disclosure: I'm really still just a green-horn PC enthusiast who is still wet behind the ears. My enthusiasm for this hobby far outweighs any real knowledge or experience that I have.
Unlike many on OCN, I've only been involved in this hobby for a little more than three years. Before May 2006, my family and I only ever bought retail PCs. We would tend to use these machines until such time as when they didn't perform well enough for our purposes (not that our performance requirements were steep; school work and word processing were pretty much all these machines were used for). I have fond memories of a late '90s Hewlett-Packard, if only because it allowed me to play Formula One simulation games (specifically, Geoff Crammond's awesome Grand Prix 2) on my own PC for the first time in my life. A good friend later rebuilt this machine into something a little bit more potent, changing the motherboard and adding a good AGP video card (the H-P ran with onboard graphics). Both the H-P and the Frankensteined PC ran Windows 98.
A couple of years later, I bought a second H-P, a Prescott Pentium 4 with onboard graphics again for school work mostly, but now also for some gaming (KotOR tugged at my heartstrings). This machine had Windows XP.
I remember quite clearly that I didn't like this second H-P so much because XP seemed so unfamiliar. I was so used to Windows 98 (not to say I was an "expert" in using it, because at that point I definitely was nothing of the sort).
Familiarity breeds contempt, as the saying goes, only this time it really means familiarity with an older product bred contempt for its newer substitute. In time, though, through constant use I learned just how superior WinXP was compared to Win98 (and especially over WinME, probably THE worst operating system I've ever tried to use).
By the time May 2006 rolled around, I wanted to build my very first custom PC. WinXP was firmly entrenched as the OS of choice, so there was no question as to what OS my first machine would use. Whatever early bugs there were had been sorted out; the only thing remotely jittery and unstable about that first time I installed an OS was me (most "first times" are nerve-wracking, after all).
Between 2006 and the present-day, I've only ever used WinXP on my machines. I had a brief period of experimentation when my personal office rig dual-booted to WinXP and Ubuntu. Ubuntu is pretty neat, but my own impatience with learning to be proficient with this form of Linux (or any other form of Linux, for that matter) currently outweighs my desire to acquire that proficiency.
I've now installed Windows Vista for the very first time. I fully realize this is an odd time to do this, with Windows 7 on the verge of release to the market. But since the OS license that I've got is absolutely free, I figured I may as well give it a run to see if it's better than good ol' WinXP.
Vista is definitely prettier. XP is painfully ugly in comparison. Colors, transparency effects, anything to do with visual aesthetics all look far far better on Vista. If there's one thing I have always admired about Vista, it's the visual aspect. XP honestly is so boring to look at now. I guess it shouldn't matter how your OS GUI looks, but if I'm honest I'd say that to me it has now become a matter of some importance.
The thing I'm discovering with Vista is how it feels slower than XP. Even on a clean install, it's not nearly as snappy as XP is. Of course, I'm not running a top-of-the-line machine, but it's no slouch, either. An Opteron 170 @ 3.0GHz earned a Vista Experience score of 5.4 (I cite this not because I care, because I don't, but only to lend some sort of context on the matter), which is a half-point away from a best 5.9; I suspect that running a 64-bit OS on just 2GBs of RAM might be just sufficient.
I'm a touch undecided at the moment as far as what operating system I should keep on my machine. I don't mind learning more about Vista, but its apparent lack of quickness at this point already has me worried that my long-held assumptions about it (that you need something close to top-level hardware to really enjoy using it) might be right on the nose.
Either that, or it's simply just too early to tell definitively at this point.
(I guess I should reinstall Vista on a RAID 0 array...)