Hi Josh,
I went from the MPS-1 to the Bel Canto Ref 1K MKI when I had the below:
Dynaudio Contour T2.5 (smooth but maybe too smooth and lacks bite, needed lots of oomphs to boogie)
Emotive DMC-1/ Musical Fidelity X-Pre
Art Dio DAC(Modified to Mensa by Bolder Cable)
Onix XCD88 (transport)
Acoustic Zen Matrix II, Ref II interconnects
AZ MC2 = Zen Digital coaxial
Analysis Plus Oval 12 speaker cables
PS Audio Quintet, Duet & Belkin 60 (forgot the entire model name)
Nordost Pulsar Points, Vibrapods, other cones and footers of various kinds
Oyaide XXX outlet, PS Audio Power Port
The MPS-1 I had were noisy with the fan even w/o playing. Its sound is quite powerful but not refined. I think it was a bit noisy from the listening position in that details were not pristine. Not an issue with HT but not my cup of tea for 2channel application. Overall, it was lacking in refinement, transparency and realistic rendering of music. I never got the impression that I was hearing the real thing in front of me.
The BC Ref 1K (MKI) were a lot smoother and very powerful. Its midrange presentation was what first drew me in on this amp. It was thick, smooth and dimensional. However, w/ my speakers at the time (Dynaudio T2.5), there was no sparkle at the top and I felt claustrophobic because space and air seemed sucked out of the presentation. To me, this amp was very midrange-centric with a fat bottom that isn't too pitch-accurate or taut and missing the upper most octave at the top. This was true even when I had the extended tweeter from Onix 123 at the time and replaced the DMC-1 w/ a Proceed AVP2 Pre/pro. Along with efforts at swapping cables and careful attention to footers helped just a smidgen but not enough to satisfy.
Then I bought new speakers. After unsuccessful attempt to mate the new Usher Be-718 with the Bel Cantos, I replaced the monos with the Nuforce MCH3SE (similar to the Ref 9SE w/ V2 boards but in multi-channel). I now have no need for the onix supertweeters. Yet, I now have details galore, spacious and transparent presentation and lively dynamics missing from all previous combos. Very neutral and faithful to the music. It allows me to hear differences in vocal inflection from the same singer on different days, sound tracks. It can be harsh sounding or warm and smooth if the system or soundtrack is inclined one way or the other. It can be soft and feathery or lively and visceral and everything in between. Fast and furious w/o residue in its presentation, very pristine and has great see-thru clarity. Also, the customer service was first rate from this company.
At this point, I have made further changes to cablings (Acoustic Systems Liveline, DACs, added balanced power conditioner to further refine the sound.
Hope this helps,
Kenobi