I think 10s to 12s is a fair comparison, and in most cases a ten (in the right enclosure )will out perform a twelve inch speaker.

10s give a defined, tight, full bass, while 12s tend to splat. My sb120 used to do plenty of splatting whenever I played modern music at any decent volume for a party.

Personally,if there was no Bose system - my rig would be 2 eon10G2s with the ROland subwoofer from the KC series.