Alright, Stefan.
Again, you've got some cool sounds, as usual. I like your usage and transformations of the primary theme. :) It was all very familiar and interesting-sounding. I think you could've done just a bit more, because it gets to be VERY familiar by the end.
I don't feel a sense of a story unfolding, so it's like a picture of a group of people. It's all interesting, but there's no central focus. Ask yourself: where is the climax? Am I really building up to it and what do I do after it? Are there any false climaxes before it to build listener expectation? etc.
Some specifics. NO high Es for trumpet in a piece this long and heavy. You may have gotten the idea from my piece, writing even up to high G. That's fine when the trumpet player is playing the role of a big band lead trumpet. It's not appropriate for legit settings: people do it occasionally for stuff like trumpet choir pieces, but it doesn't happen in quintet. If you really really want that note here, you have to score it for a higher trumpet. I'd say Eb trumpet, any lower is too low, any higher is too thin-sounding elsewhere. But of course, you have to then decide: do you want the guy to switch to the Eb in the piece, or play the entire thing on Eb? But you really should know what an Eb trumpet sounds like before making that decision, because it's not the same thing.
I think many if not all of your borrowed 3:2 rhythms don't add anything to the piece except the odd feeling of a polyrhythm. On the flipside, I think every single 4:3 with sixteenth notes should be rewritten as 12/16 bars, because that's what's really happening. Also, why not turn the measures leading up to m.43 into a metric modulation? You totally set it up, and then disappointed us.
Final critique: I don't think either key change worked. The first one would've been alright if there was more than ONE pitch being played at the key change. The second one simply has too many people jumping weird, outside intervals.
Thanks for sharing, keep hacking!