I own the Soundsmith MMP4. I visited The Soundsmith's showroom in Peekskill and auditioned the MCP2 and the MMP4. At the time I was looking for a better MM phono preamp, I have been switching back and forth between the Pro-Ject Phono Box SE II, the Bellari VP129 with a NOS Mullard, and the phono board in my Primaluna Prologue. I have a VPI Scout, a Primaluna Prologue II, Totem Mites, and I am mainly listening to high output MC carts, I have the DL160 and a first generation high output Benz Micro Glider and this week I just got the Soundsmith Otello. I am incredibly impressed with the MMP4! I dont know if it is the 43db gain (the phono board's gain is listed at 42db the phono box SE II has 40db gain in the MM setting and the Bellari is 30db) that really helps my high output MC cartridges reveal their full potential. I love the MMP4, it reveals greater details in the music, and trumpets and horns sound amazing. I wrote a longer rant about my experience with the MMP4 here:
http://thevinyladdict.blogspot.com/
http://thevinyladdict.blogspot.com/