difference between ATC SCM7 and SCM12?

Curious if anyone has experience on the sonic differences between the 7s and 12s?

Been auditioning the 7s in place of aktiv Ninkas and LOVE them, but a little to small for the space they're in.
How big is your place? I'm using original passive ATC SCM10s in a 20+ X 14 (speaker is on the long side wall.)
and it works fine.
Did you go with the ATC SCM 7's or the 12"s or just stay with the Ninka's?

I ask because I have been considering the 12's or the Ninka's.
I definitely want the 12s, but am waiting for sufficient cash flow.

Ninkas, while being very pleasant - can't hold a candle to the ATCs in speed or midrange. I currently own a pair and they're gorgeous, much nicer in appearance than the ATCs, and shielded.

If you go for the Ninkas, the upgraded bases are a MUST!!

what is a good integrated amp to power the scm7's?
the 12's are a hole different league, they use the same driver as the 20's, what a great soundstage, incredible!!!!!! I use the 12's for my fronts, 7's for my rears. The 12's are give a much fuller soundstage! I run a carver 200x 5 amp and can't pull everything these speakers want though!
I went with the 7's because I felt the instruments simply sounded more accurate...I a/b-ed the 7's and 12's, although the 12's obviously had more behind them...it was the trade off.

Amp's anyone? Still thinking about the Creek integrated, Classe CAP 150, or the Primare I20...