It would be great if you continue to report back on your experience with the M225s. Frank Van Alstine is quoted in the Absolute Sound review as saying that one of the goals with this amplifier was to, as much as possible, completely eliminate harmonic distortion. And I'm guessing that this design goal in conjunction with the amp operating in Class A...possibly up to 20 watts are the reasons it has been getting great reviews.
It doesn't seem like anything revolutionary, but then again as with most things audio, the implementation is the key. To his credit, Frank says that this is not the be all end all design and it has been his experience that they are many designs that have ended up with excellent amps.