Predator BK2 for me...
I don't like the shorter butt of the Mezz.
I owned in the past the Mezz Power Break I and didn't really like it, the shaft was very heavy and generated a lot of cue ball deflection. But it did had a massive break, and that was with a leather tip.
I like the shaft taper of the Pred. BK2 (closer to pro taper) better then most current break cue that offer a "strong" taper. Mine is 17.9oz with forward balance which is the way I like my break cues, I feel most comfortable with it.