Sim Moon 400m amps..any thoughts

Moon make very good amps - which is why I ended up getting the P8-RS pre with W8-RS power amp(s).

Must confess I've not heard the mono's - but the trickle down in technology will likely mean that they are well thought out.

I've always liked the way Moon amps retain the emotion within performances and with so much power on tap - you can drive any speaker easily - they really do take a solid grip on the speakers.

Despite i didn't go to RMAF, but the guys at soundstage have made a nice review about them.
http://www.soundstage.com/index.php?option=com_content&view=article&id=231:simaudio-moon-400m-mono-amplifiers

I am interested in the 400Ms as well (bumping this thread from 2011).

Its interested to see on the surface that they put out 400watts at 8 ohms but only 650 at 4 ohms. Sim is known for having stout amps which double the power from 8 to 4 ohms, so this is an interesting design.

Robert Harley, on another forum, pointed out that the design of the 400M approximates more of a "bridged" mono design than a true "dual mono" design of many of their other high power amps (W3, W5, W7, etc). Its more expensive to make the dual mono powered design, but does it sound better?

But, I do like that the 400M, despite an A/AB design, puts out the first 10 watts at class A, rather than the first 5 watts as in many of their other designs. But heat usually follows Class A output, so I wonder if the 400Ms get hot. I suppose they might since Sim went with a mono-block design rather than a dual-mono design.
thoughts?