I've used mine in many different rooms over the last decade+. Dimensions have varied from 10' x 12' (a spare bedroom in an apt) to 14' x 35' (combo dining room/living room in same apartment) to a pair of 14ish x 20ish dedicated listening rooms (one w/high ceilings, the other lower), as well a few others in between. The speakers will sound a bit different in each setting, but they always retain their fundamental strengths (remarkable midrange clarity and impact) so long as they're reasonably carefully placed and the room isn't a nightmare.
For me, the trade off has always been maximizing imaging vs octave to octave balance. Pulled out into a larger room, the imaging can be really fantastic, but the bass may lose some weight. Backing them up to the wall behind them will generally restore weight to the tonal balance with some diminution of that wonderful staging/imaging. IME, smaller rooms generally make the issue moot - you'll get the bottom end weight at some cost to the image. No choice involved.
I've managed to make the speakers sound very good in each setting, but the bottom line is that I got my best overall results in a room with dimensions nearly identical to yours.
One more data point for you.
