Is my room OK for Magneplanar 3.6's

I agree with Schipo. I tried to fit the much smaller MG12s in an 11X13 room and felt it was too small a space. They need room.

I tried 3.5s in a similarly sized space many years back and could never get them to behave properly.

Not even close. Go with the 1.6 or 1.7 instead

Square? wrong shape.
I think I made that answer in another LD thread.

Sorry, man, I simply think you've got the wrong room for the right speaker.

You may be able to make MMGs work.....save a BUNCH of money and have full upgrade credit for a year, so if you want to than, you can trade UP to the than new 3.7s

I've had panels in as small a room as 100ft/sq and it was miserable. And that was with MG1s.

Probably too small, especially being square. I have a pair of 1.6s in a 15 x 21 x 8 room. 6' off of the front wall, 30" of space between them and the side walls. My head position is 2' from the back wall. It sounds good, but not as good as when they were in a larger room. The back wall is key. They say 3' will do, but that is a stretch in the same way Magnepan claims that one can get away with only 50 watts or so. This is with wall treatment behind the speakers fwiw.