The future artist MIDI looper is like a looper pedal, but for MIDI notes and knob movements. The matrixbrute has full midi implementation for the knobs, the looper has been a great companion to the matrixbrute. You can record your notes, loop it, quantize it if you want, and then tweak the knobs, even record the knob movements too. You can use the sequencer on the matrixbrute, and record your transposing the sequence. The sync works well slaving the MB to the midi clock on the looper- you get the sequencer/arp tight with the looper, and sync the lfo's too. It's been a lot of fun!
http://www.future-artist.com