thanks for the input ajzepp, appreacited. I love my mapletree as well but I have a Butler 2250 amp and I hear that the SAS 10A really plays nice with it......apart from yours, I've also had some input from some of the Elder Gods here and they also give a thumbs up to the 10a... 
Hi Alex,
I believe the 10A is unique in that I checked and minimized all forms of distortion.
For instance, not only are there harmonic/intermodulation distortions, frequency response distortion (poor frequency response), soundstage distortion which includes width and depth, dynamic distortion, DA (dielectric absorption), but masking distortion as well.
Masking distortion is just as its name implies; that of masking real inner detail. Some designs give the illusion of inner detail but is actually harmonic distortion or other distortions like DA (dielectric absorption). But there is a difference that becomes apparent.
Real inner detail will, for example, reproduce the echoes, room reflections of the recording venue whereas harmonic distortion will not. Another added sense of realism accompanies reproducing real inner detail.
Hope this helps.
Steve