I quite liked it, I enjoyed the piano personally. =P Though it should slowly lower in volume as the song goes on up until its solo (or whenever it has variation).

However, 1:00 felt too jarring/off to me. You had these complicated layers of rhythm right before it, and suddenly all the instruments were sort of banging the same thing. Having one of the melodies counter with the main tune or having a background instrument play something that was off-beat would've made it transition better, I think. :]

Aside from that, the improv sections were all nice. The odd chords worked fine and really gave depth to the piece. The performances were pretty spot on. SO...4/5 for me. This must have taken a lot of time, and it shows.