I'm a huge fan of the Thunderbolts comic book from Marvel; classic Thunderbolts, that is, where the villains were posing as heroes in order to effect their larger, more nefarious plot to rule the world.
I have been wondering how it would work to run Hell's Rebels TBolts style. It seems to me like the best possible scenario of the APs (I'm not sure Hell's Vengeance would work quite as well in reverse, for instance, due to the way the plot plays out). I think it could provide some really interesting RP opportunities as the "heroes" try to maintain their cover amongst their allies, particularly as they level past 4th and now need to worry about magical alignment detection as well as more mundane means, and it might provide some interesting alternatives to combat with the villains of the piece- negotiating with some groups to stand down in return for making them a better deal when the "heroes" wind up on top, etc.
Has anyone else attempted something like this? Did it work out, were there problems indemic to the way the APs are structured that made it difficult?