Luxman M-10X Stereo vs. Mono or C900U

Anyone with the M10X can quantify the difference in stereo mode vs. monoral  mode? 
I currently have a Lumin T2 which I can use to connect directly to M-10X and use it as a preamp. The speakers are Kef Blade One Meta.  Is it better to put the money toward a second M-10X and run them in mono than getting a proper preamp C900U? 


I did not. I wanted to stay with SS and the C-10X is the natural pairing of M-10X. 

How did you like the mono compared to stereo?  Is it worth it to go mono with the M10x?



“Is it worth it?”  
I guess that depends on your financial situation and how much you like the M-10X in stereo mode. To me, and I listen to a lot of jazzy and blues and some pop, the difference is there. If you come from an M900 to M-10X in stereo, you will immediately notice the low end is more punch. Having two M-10x in monorual kicks it to another level. Depending on the recording and the music, the soundstage is wider and deeper. You get more depth with the M-10X in mono. 
I didn’t run the M-10X in stereo for that long before I got another one. I ran it for about a month and at the time, I also had the 595ASE. After receiving my M-10X, I didn’t use the 595 at all. The M-10X just sounded better all around. The opportunity came up when a local guy had a M-10X new in box so we worked out a trade deal. I like the M-10X enough that I don’t mind having another one for another system down the road and get a preamp for it rather than keeping the 595 integrate. The 595 is great IF you don’t listen to the M-10X back to back at the same time. I’m running a C900U right now while waiting for my C-10X to arrive. If I ever do another system, I might break up the two M-10X and get a used C900U. 
The difference is there in stereo vs. mono. If I have the fund for another one for a second system, I would keep running the mono pair in my main system. However, I also don’t mind to split them up and run them in stereo in two systems.