Your list looks pretty solid. These sleds are incredible out of the box. On our shop build we kept it simple so far. Its a 155 2.6.
Unit 6 Ti Can. Loud but LIGHT. 3# IIRC.
Hillclimb braces - These things have taken an impressive beating and the rails are still straight.
New rear bumper (coming out this summer) I broke the carbon one the first day I took it out.
Offset axle and 9" wheels. Who doesn't like bling?
It could really use some upgraded shocks, or springs at least. I felt like I was going to snap the sled in half bottoming it out so hard when jumping it 100+ feet in spring snow.
We try to keep the sled stock and no change things until they break, good opportunity to see what needs attention and what holds up. I have always been a polaris critic/hater, but If i went out and bought one today, I would be hard pressed to buy anything but the AXYS. It just works.
Nick - IceAge