The smaller room is too small for any of the Avantgardes - you need to sit a minimum of 10' from the tweeters for proper integration, and the tweeters in that case would be 12' apart if proper ratio is used - meaning that the small dimension of the room must be 14' or more.
As another owner has noted, the Duo Omegas have no practical limitation on bass extension; I find that the bass integration issue some cite is actually due to poor set-up, crossing the subs over too high, and/or setting subs' volume level too high.
As another owner has noted, the Duo Omegas have no practical limitation on bass extension; I find that the bass integration issue some cite is actually due to poor set-up, crossing the subs over too high, and/or setting subs' volume level too high.