My XBA-30's matched up with the C&C BH is the best sound I've heard to date.. On high gain with the LF switch on makes it a perfectly complete sound with a huge soundstage and amazing separation.. And the bass is just next level.. The E11 on the other hand made things too muddy and took some micro details away when I had it with the XBA-3.. So who knows =)
I didn't experience any sound degradation from the XBA3 + E11 combo. Maybe you associated smoothness to loss of detail?