There are a few more still active on SF (Vincent, TheEnd, MK404, probably a couple more I'm forgetting, etc.), but the "oldbies" are a dying breed. Well, at least the ones just from FESS. There's handfuls from the other boards still around too, since none of the boards were really friendly with each other back in those days. A decent majority picked one and avoided the others, at least until lack of activity or closures prompted moving.
Also, Proboards FESS ("FESS1") was pretty bad in retrospect. I'm kinda glad that I didn't show up until the InvisionFree era ("FESS2").