I have owned both and currently own the 6505+. Its a real workhorse, sounds great in a mix and I think its an all around great amp. But I actually played a new DL100h at rehearsal the other night and it sounded great. Not only that it was easier to play and more forgiving. Anyone have experience with these guys? After playing the Marshall my 6505 is feeling stiff. Although, I guess it is a tighter amp so there is a tradeoff.