The Behringer has more bang for the buck with 2 expression pedals and channel switching relays built-in. The negatives are it's larger than the Midi-Mate, no phantom power, and waaay harder to program for novice users than the M-M. If you go this route you're probably gonna want the PC based programming software a frustrated yahoo group user wrote. I believe there may be a phantom power mod too?
The Midi-Mate is smaller, easier to program, you can name your own presets, and you can phantom power it. The negatives are there's no channel switching relays and only one expression pedal input and you have to buy your own pedal.
The buttons on both units have virtually no feedback when pressed, in other words no positive click. There's other less important negatives both units share, no need to get into that.
For a little more cash you could get a Ground Control Pro and a couple EB pedals and be done with it.