Brom actually introduced me to Roll20 some time back - we were playing his "Bring Me That Horizon" game, actually.
I wouldn't call myself a "frequent user" by any means, but, following my first experience with it (which was way more enjoyable than I had imagined it would be), I gained an appreciation for it that I hadn't expected. There's a bit of a "learning curve" involved, I think, but once you get past figuring out how everything works and such, I found it a very entertaining and useful forum for playing "live" or even simply as a supplemental sort of tool for PbP.