I found a 4ohm B212neo on CL for $250. Great cab for the money. At the time I was trying out a PF500. It worked great on an 8ohm cab, but when I plugged it into the avatar, it would cut out (limit).
Probably just related to that particular amp. Others use them with great success, but that's what happened to me.
I believe I have read something about not so hot frequency response in the 2k hz range due to the crossover to the tweeter. I can't say that it bothers me.
I'm sure there are better cabs, but I'm thinking you'd be hard pressed to make more noise for $450 OBO. If they are neo then they are pretty easy to schlep as well.