Revision 3 Atma Sphere amps

What experiences have people had who have upgraded from an older rev Atma Sphere power amp to the new rev 3 versions? What sort of differences did you hear?
This question was recently asked on the Atma-Sphere owners group ( Somebody indicated that there is little difference between later revision 2 and revision 3. Check out the site. It's a great resource for A-S owners and anyone who aspires to be an A-S owner.
In case you haven't yet seen it, Ralph recently offered his perspective on the difference from rev.2 to rev.3 at the ASOG's site.