I have used both and I have to admit they are about equal in my eyes.
I used a blank top of the range BDM around 2 years ago and that absolutely flew! It was a very lightweight cleft, must have had around 40mm edges and was 2lb 9oz, no concaving and a huge middle, and that is up there with one of the best bats I have used, shame the player took it back to Aus with him!
I have also used a BAS Grade 2 (cant remember the name now) in the same season, but it was not as big as the BDM, but around the same weight. The ping was nice and i hit a 50 with it, but I would go with BDM personally.