This is midi? Man, someone is really pushing the envelope.
My complaints can mostly be reserved to over-reverb and hearing a lot more of the subby thud on the upright bass than the actual notes themselves. 1:41's reverb is a huge example of reverb overhang.
Overall, however, nothing necessarily sounds bad, barring maybe that snappy doot-doot lead trumpet, un-muted.
I would probably recommend a different e-guitar than Halion's admittedly not bad jazz guitar. Ample Sound's AGG2 and others are far superior after having done some demos.
Compositionally, this is a treat. Starts off with some sweet swing -- great ghost notes on that perc. Sax solo through 0:37 is blazin', almost sounds human, which is a testament to your writing. Cannot say the same for jazz guitar. Drum and bass solos are great with the exception of the aforementioned subby frequencies on that bass being out of control.
Around 2:04 I would have gone with a bit more relaxed releases and probably humanized those chords a bit more. Bass writing through that section is wonderful.
I'd have liked a little bit more of a hold on the final note of the outro.
Overall, great piece. Really enjoyed it! Only wish I had more to write, haha.
Thanks for coming out to NGUAC!