Dan D'Agostino S350 vs Luxman M-10X

I've listened to both and they are different enough to need you to listen. Both are excellent. but I would go for the luxman because it has better detail restitution and it sounds subjectively faster.

Mind you, I listened to them driving Goebel, Magicos, and Aperturas -- not your speakers.

Again: try before you buy, it's worth it in this case!

I've not heard the M-10x, but I have heard Luxman amps and D'Agostinos and to my ear they were a lot more alike than different with Wilsons. 

I mean, one is $45k and the other less than half that. These aren’t really comps.