No direct comparisons, but I had a BB2 for a fairly short while, and it's just bizarre how much such of everything a small box can produce. I played an RAF hangar with just it - I declined the PA, just to see - and it was plenty loud with my Streamliner 900. I did feel it was playing at my shins, though - I should have used the angle stand I used to use with my Schroeder, but I'd forgotten to bring it. I paired it with my Gen1 Compact, and that was nice. It's definitely full range - I'm not a fan of horns, which was one reason I moved it on, but if that's your thing you'll not find one wanting. I had it switched off...
It might look a bit silly under a full rack, tho...
FWIW, the only thing I'd change my Bergs for is a pair of Super Compacts.