tracks
Well, from experience of riding stock sleds to my turbo Rev's in the mountains the best all around track for a stock 800 Rev is a 151x16x2.25. You have to remember that your polaris is a 151x15 and that is equal(as far as surface area on the snow) to a 144x16. Thus, in comparison, a 151x16 is equal to a 162x15. As people on here have said, 144 will boondock slightly easier than a 151, but in my opinion pretty close to the same. Longer track you get the more effort it takes to boondock, even when the weight of the sled is close to the same.
Alot of my buddies ride polaris with full SLP setups, Polaris and SLP should merge together and be one...ha.. and my dads backup sled is a 06 900 with SLP setup,clutched, NOS, holz w/ fox floats all- round, and a 166" and it will barely go were my friends 800 151 REV w/ a MBRP can, will go. And that 900 will wear you out after a couple hours of riding. You will love a 06 Rev and there will BE NO COMPARISON to your old polaris. It might take a ride or two before you get the hang of the rev.