I owned both the 55 and the Premier 11A at the same time. Speakers were stock Acoustat 1+1s. I found the 11A superior in the bass: tighter sounding, but not too tight and of course it had more power.
However in every other way and overall I clearly preferred the 55. Through the 1+1s, it was richer, brought out the lower mids, and was generally more musical.
However in every other way and overall I clearly preferred the 55. Through the 1+1s, it was richer, brought out the lower mids, and was generally more musical.