Sound Quality: Atma-Sphere MA-2 vs. MA-1

I have the distinct pleasure of sharing my home with a pair of Atma-Sphere MA-2 MkII amplifiers. Because I have the MA-2's, I'm occasionally asked about sound quality trade-offs between these and their 140w brethren, the MA-1's. But, I've never had the opportunity to listen to a pair of MA-1's and so I can never give a good answer other than the usual considerations of the -2's ability to drive almost any load, increased power, etc.

Has anyone had the opportunity to listen to BOTH? And if so, can you share some thoughts as to the difference in sound quality between them, all other system factors being equal?

I know, for example, that the MA-2 uses Caddock resistors and teflon capacitors, but that these parts are not standard with the MA-1. Also, there must be some differences in the input stage as evidenced by the MA-2 MkII using six 6SN7 tubes and the MA-1 using four. Seems like these issues, and perhaps others, would affect the sound in ways that go beyond power output and ability to drive that power into varying impedance loads (for better or worse). I'd really appreciate some feedback on this issue of sound quality differences just for my own education. Thanks!