I can say I have had a far better experience with Windows XP then I have when any other previous Windows operating system, I prefer to use it before any other Windows OS, but in case I have need of running older software I have Windows 98SE in a virtual machine. Yes, I can say Windows XP is bloated, but you can turn off alot of the resource hogging features that make it look like the Fisherprice OS it is.
Stability? under Windows XP, my system has never locked up once, but it does get slow at time due to extended use in which a simple restart cures it.
if you install it on an older machine, don't expect alot of Windows XP, you would be better of With Windows 98 or 2000.
With Windows 98 I have had a poor experience with, the BSOD was constant with 90% of the time it being explorer causing it.(not internet explorer):P and then its ability to "lose" files.
But in reality, there is no need to push one or the other, if you are using Windows XP and you like it, Great!
if you are using Windows 98 and enjoying it, Excellent! It really doesn't matter what others think as long as you are happy with your experience with it and it does everything you need it to do.
By the way, Go Slackware!