ATC SCM7 vs SCM11 ? Which one would you choose?

My room is  12'12" x 19'3". Thank you,

Wow, it's great to have a direct interaction with the official distributors of ATC in USA. Thank you very much for your response! Actually I just bought a pair of SCM7 from a seller in USA AUDIO MART. That seems to be the only way to experience first hand the ATC sound as of now without buying the much expensive SCM19 or going to the PRO alternatives. No one seems to be selling the SCM7 or the SCM11 brand new as they are back ordered or non available. I paid "only" $1,000.oo for the SCM7 as they are slightly used and my strategy is hopefully to use the SCM7 as the "entry drug" of ATC speakers and then maybe bought a pair of SCM19 or higher in the line with a SCM40.2A. It just depends of how much I'd like the SCM7s. I've read a professional comparison/review between several speakers including the SCM7 and the LS50 an even as the LS50 were highly awarded the SCM7 won the contest.

I love my KEF LS50 speakers but I'm really eager to try the much recommended ATC sound. I think I will be ok with power requirements because my amp is a NAD Master M22 V.2 that provides 300 wpc at 8ohm. 

Best regards from Costa Rica! Believe it or not, some other audio enthusiasts here know about the ATC but we know it's an impossible dream (mostly a non viable business) to have a direct distributor here.

Please excuse the double post. Hi. I would like to thank everybody for their helpful answers and specially to all of those who recommended me ATC speakers. After reading your opinions and others from similar forums, since no SCM11 speakers where available at the moment (3 weeks ago) I found a pair of SCM7 speakers (V.3) used but in perfect condition. WOW, I've heard many speakers before, including my KEF R7 and LS50 speakers, and even though it sounds cliche, I can really say like other forum members had said, that these ATC are in a completely different league of their own and are BY FAR and NOT EVEN CLOSE than others, the BEST speakers I've heard in my life.
With my first hearings and comparing them with my LS50s, I thought the sound produced by the LS50 was linear, I mean, all the instruments sound at the same volume level but in their different positions and with the SCM7, some instruments sound specially louder than the voices but in a very nice way, almost 3 dimensional where I could "touch" the instruments.
After more hearings I still think there is like a V shape or something like that where voices sound a little less loud than the other instruments but in other songs the volume is equally distributed, BUT, that's just an observation. The main feeling with the SCM7 is that they provide an uncanny neutral sound WITHOUT being fatiguing at the same time. Everything sounds "like the real thing", sometimes "too close to reality" but without any harshness and almost all kind of songs from all kind of recordings sound great.
ONE GREAT THING these SCM7 speakers also has is that they provide a superb soundstage and instruments separation way beyond their physical space.
Anyway, this "review" is the least technical one you might find because, in plain words, the sound they deliver is MAGICAL, there's no better word that come to mind. They make me feel a special joy because EVERY SONG I've heard, even those I've been hearing since I was a teen in 1988-1989 and have been hearing through all the years through a lot of car speakers, home speakers, headphones, etc, SOUND ABSOLUTELY NEW when heard with the SCM7. It's the excitement you could get if, suddenly, all your favorite movies could be seen, in a future, in full 8 or 16K with 3D, I mean, a complete revelation that makes you PLAY and TOUCH the music if you know what I mean.
These SCM7 speakers have been an unparalleled sonic revelation.
My search for the perfect speaker is over, I think. From now on, I'll be concentrating and other ATC models as an upgrade.
Best regards,