@rman9 That is great news--glad your dealer came through for you! Not surprised at all that you loved the demo and C900U in your system. Your listening pleasure should only grow from this point. Exciting!
I love the M800a; it's driving Joseph Audio Perspectives. It's not as detailed and not quite as transparent as the 900u, but sounds more natural to my ears. It does run very hot though. There's so much heat dissipation that it almost feels like air is being gently blown through the top vents. Maybe an M10x will be in the cards for me if I tire of having a space heater in my room. Still, I think it's a shame that Luxman didn't keep at least one highly class A-biased power amp in the line up.
Please do let us know what you think of the M10X after you've had some time to get familiar with it in your system. I think you might be the first person on the internet forums to share direct experience with it! All of us Luxman fans have been waiting for reports. 😄