The biggest annoyance to me about LMMS is that it only lets you have one piano roll open at a time. When I'm working with multiple tracks, I'd like to be able to open additional windows for each track so that I can line them up vertically. For me, that would be a lot easier. I could make edits to one track, edit the other track, go back and edit the first one some more, etc., without having to keep opening things. Being able to see them all at once would also help me work faster.

Other than that, I really like this thing. Good job!