You rock my socks!
Really nice! You've got that uber-cool, but still upbeat flavor on lock. Simple but very effective. The Guitar/Bass combination is just right too. It is very easy to go overboard when doing tracks like this. I've got just a few little possible tweaking suggestions.
First, the low brass hits are an integral part of the piece, and really add to the badassery. I would suggest boosting them just a little, not in volume, just punch. You are almost-but-not-quite to that gritty, low, crunchy, awesome hit. It would really just be a little sound-design project. You could double it an octave lower with more brass, or something else that has punch.
Second, the drums are just a little flat. They are well programmed, but they SOUND well programmed. If you cut off the tops of the velocity, and boost some others to more closely mimic live drums, the drums would draw less attention to themselves, and make the rest of the piece shine through.
Just a few little suggestions. Take them with a grain of salt. This loop is genius! I love it, and I wouldn't have reviewed it if it weren't a totally top-notch loop.
BTW, the organ at the climaxes, and the call-and-response with that little woodwind section really make this piece for me. 5/5 10/10