personally, i think sweet lifelike mids from both the 11a and the ultraliner 12's are about the same. the biggest differences in my system are that the 12's control the bottom end better and the the music is just a bit more detailed. i don't really attribute the latter to the amps per se, but i think the added power helps run my speakers more efficently and, thus, brings out the best in them. i hope that's helpful.
