C J 11a VS 12s does the 12s sound better

I own a C J 11a and I'm woundering is the 12 just more powerfull or does it out perform the 11a in othere areas?
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.
I had an 11a replaced it with an mf2500. Significantly more bass response especially noticeable during Tachovsky's 1812 overture with the digital cannons. However, I feel I lost some detail in the mid and high end, again noticeable during "Vivaldi the four seasons of" with anne sophie mutter on violin. I would hope that the 12's or 8a's (soon to be replaced) would bring back the detail(mid and high end) along with the bass control of the 2500. I an using a cj premiere 17ls as preamplification and thiel cs3.6s.
I owned a pair of 12's and have heard the 11A. In my opinion the 12's sound much better. The added power seems to work magic. It may be the fact that I like my music a bit bass heavy but the 12's do satisfy. CJ 12's on female vocals are hard to beat. If you have the funds I do recommend the upgrade.
I started out with one 11a, and when I had the itch to upgrade, I compared the 12's to a pair of 11a's bridged to mono. This bi-amp set-up was hands-down the winner. You don't get quite as much power as you do out of the 12's, but the bass depth and control improved quite a bit, and the midrange and treble were much more liquid and detailed. I've been completely delighted. I was back at my dealer the other day and auditioned the Revel Studios with the 12's (since he only has one 11a), and when I complained that the midrange sounded a bit congested, he told me I was spoiled by bi-amping. Definitely worth a try.
Pleas explain to me "bridged to mono". I thought the 12's were basically two 11's in mono. When you biamp do you mean for highs and lows?