I used Hero System for a Dresdenverse RPG at Gen Con last year, and it worked fairly well.  Of course, i've played Hero System for many years and find it to be flexible enough for just about any setting.  I plan to run again this year, hope that I can get the new system with enough lead time to learn it and convert everything.  Of course, I run a very "rules light" style anyway, so I may not be the best example.