I've been working a bit with qtractor, and Rui's doing a good job with this. It's a seamless port chain with LSampler and Jack, and that figures strongly in the connections box inside Qtractor. Easy and quick to setup. So far so good. The track layout is simple and easy to follow, and the distinction between mid and audio works well. I'm doing a light ensemble in it at the moment, and all seems to be ok.
2 caveats.
I would hope in a future release that Rui considers changing the midi track format to multiple channel per track, and reflects this in the piano roll editor, with options to click on a note and change the midi channel. for some one like me who writes classical stuff, and uses a lot of articulations per section or instrument, this would cut down the channel count considerably, and make this fine programme even easier to work with.
Second, Rui, would you please consider adding shortcut options to most of the functions. It would be terrific to use Keystrokes to enact things, and really speed things up.
Rui, if you read this, i'm enjoying using qtractor, and thanks for the chance. I would suggest anyone else reading this give qtractor a try. It's very easy to use.
More to come!
Alex.
(Now it's back to writing a demo....
)
anyway, i believe i've answered your questions over on 
i've been a win16 and win32 programmer almost half my pro-life but got free 10 years ago. curiously, i quit smoking precisely by that time. could it be coincidence?
and to put things in the clear, most of qtractor layout and model is severely inspired from that experience. ah, just look into the midi instrument map support on qtractor: it's plain old cakewalk's .ins files that goes in there, see? 
