I guess I'm a Beretta nerd as well, as actually I knew that. But yeah, for holsters they should all be pretty much the same.
The newer BT's have better checkering on the grips, but the 2 slot rail looks wrong to me. I guess it's just because of the 92A1. I don't mind the single slot, or the triple slot A3. The 2 slot just looks kinda queer. I guess it's just because I'm so used to see it on the 92A1, and I'm not a huge fan of that gun. It seems out of place on the BT.
-Cory