This is interesting topic.
i have made a midi controller with Uno R3 about one year ago (http://popo.webatu.com/
) and now i'm starting to think about building some kind of midi Foot Controller.
I don't know much about electronics or programming and i had A LOT of help here from the forum to complete this last project, but it was also a great way to learn by doing.
The thing is that needing a serial to midi converter is a little bit annoying. It works, but there are some inconveniences (like for instance, not everyone has Processing and a Serial do Medi Converter Sketch).
So, when i heard that Leonardo had native ubs hid i was excited about it.
But now when i have read your thread i was a little bit less enthusiastic.
Is it not so easy to use the Leonardo to create a "Plug and Play" device?
If i would wrote a sketch that works on Uno R3 would it also work on a Arduino Leonardo?
My idea is to create a foot controller with maybe 8+2 foot switches, maybe 4 "banks" and some LEDs to use with softwares like Ableton.
Would you say that Leonardo would be better than Uno R3?