Buzz's midi is not great. Every generator has to write its own midi support, and many of them don't have it at all. Also, I'm not sure I've ever gotten it to record/playback to external midi devices like the sequencer it's supposed to be.. though you probably aren't interested in that.

One thing it actually does right is that you can assign any setting on any generator or effect to any MIDI control. So I can use the 40 knobs and sliders on my synth to control everything in realtime!

..heh, said controls are pictured above.