I like it quite a bit, although towards the end it gets a bit dull in comparison to everything else, but not too much mind you.
The biggest problem however is the trombone part, being as it would be incredibly difficult to do some of those runs at that tempo without it sounding like a glissando. Unless, of course, that's what you're looking for, then lol nvm. Although if your teacher didn't say anything about that then maybe I'm just misinformed. I don't play trombone, so I wouldn't know, it just seems a bit too fast for it at times. Tsuno would know though =o
Overall I think it's pretty great. Interesting brass quartet pieces can be fairly difficult to write, so I definitely have to compliment you there.
You've inspired me to try something. :3