I have used Vector linux before (VL5.1 maybe?) but then I migrated to Ubuntu and Damn Small Linux before I switched back to XP recently. Anyway, my friend donated his PC to me few weeks ago and I just installed Vector Linux 5.8 Std Gold yesterday on this one (P2 500Mhz 256Mb Ram) and everything works fine!
Installation was simple, every program is very responsive and loads pretty fast, including GIMP! Boot and shutdown is also fast, every program that I need / love (such as Opera) is already installed by default which is great!
I remember that back in 5.1 the user can choose/switch WM between Fluxbox, IceWM and something else (I forgot), I think that's pretty cool!
So next step for me would be to browse around the forums, learn as much as I could about this wonderful OS and I'll see you guys around!