Plus 2 @ghdprentice, I bought a C900 amp as Jay and others were all about it 4 years ago. I burned it in, and in and in, but the sound was exactly as GHD reports. I had Wilson Sasha 2s at the time. I sold it within a few weeks and bought ARC 160m s. I have since moved onto a Gryphon Antileon EVO and i'm happy. That said I was told that you need to put Luxman preamps with a Luxman Amp which I did not do. So my story is incomplete.
Any real experiences with a Luxman C900u and C10x?
I'm in the market for a new preamp and have the M10x and am leaning to the Luxman C900u or C10x. There aren't many dealers around me that have both for me to try and there doesn't seem to be much info on both online (i may not be looking in the right places 
)