Absolutely top notch - specifically for MIDI management. Route anything to anything. I've tried every live host on Mac out there that I can find - they ALL had issues. I am heavily into arpeggiators & step seq's. NORA and NUMEROLOGY both have complex GUI's involving tabs and resizeable pages. I did not find a single live host that could successfully present those to me until I tried MULAB (except MainStage - but MIDI routing virtually non-existent). Like they say, everything just works, no surprises except happy amazement. Completely intuituitive - you can go a long ways before you need to crack a manual. AND it comes with MIDI tools that are essential for complex routing, such as a MIDI monitor. With Ableton they won't even give you that until you buy the most expensive edition - they sell you a carpentry kit and then withhold the hammer. And speaking of step-seq's, the one in MULAB is a monster.
This dev has mad coding skills and deep insight on what is necessary, what should be simple, and how to make it rock solid. Making it available as a VST on MAC changes Everything - MULAB inside LIVE is better than sex. OK, well, better than coffee.