I received my MP32L from serdashop yesterday! Very nice to have a single device that can be switched between old, new, and CM roms, to replace my MT32 and (partially working) CM500! The sound font support is a nice feature for a truly compact solution, but I will still use my SC55 for General MIDI.
One issue I had with the hat itself is that the display would not function with the cover attached. It was driving me nuts, but I discovered that one pin was not fully soldered... attaching the cover would press down on the display and cause the pin to shift slightly, breaking contact. A quick resolder job fixed it.
I tried several games and had no issues whatsoever (connected to a PCMIDI card). Even troublesome games like Wing Commander are working great!