The phono works with both MC and MM, but I can't comment on phono quality since I have limited experience in the area.
The RR2150 is a very flexible unit and I like it.
I use it as a preamp for my main system, integrated amp for my desktop (via Y adapter), and an input switch box for the rest of the house via the external processor output (using their OAW wireless system).
I have the headphone output connected to my subwoofers (I am not using the integrated bass management).