It seems all 3 choices are very good. I may have missed it, but I don't think anyone has expressed "why" they prefer one over the other (well, except for Brian, but we all know what that's worth). So back to square one. Being the HB-1 MK2 and CMB-170 SE the most popular, and according to my research, here are the characteristics I gathered when compared the 2:
Wider soundstage, More Dynamic, Better for HT application, More sensitive, Nicer Finish/Looks, More difficult to set up (for sweet spot) , Not as seamless surround, Smaller sweet spot but lesser off-axis loss, probably sound better in medium sized room than it does in smaller.
More musical, a tad more neutral, easier to set up (for sweet spot), better surround integration, bigger sweet spot but may incur greater off-axis loss, not as dynamic. Probably has an advantage in smaller rooms.
Both offer good small to medium room SPLs and good bass when paired with a sub.
Please feel free to dissect or trash these comparisons. Hope it helps to get back in the discussion.
Yamaha RX-V673 | HSU HC-1 MK2 | HSU HB-1 MK2 - LR | Pioneer SP-BS22-SLR | BIC RtR-V44-2 (Presence)