So, I picked up a 2012 Pro RMK 600 with only 68 miles on it, max speed registered on the guages at that time was 50 mph, didn't even think to check the belt, took it out to ride it and the belt had been trashed. Yes you can tear up a 115 belt because the previous owner to this sled did! She was some rich lady from New York who rolled into Aspen, bought the sled, went up Indpendence Pass twice, probably got stuck somewhere and sat there and ate a hole in the belt! Dang it! Expensive for me! (Price on the sled was awesome so who cares, right?) It was a nuisance though because I hadn't purchased a spare belt yet so I rode it all day with the bad belt.
I've used the 080 belt on my '07 Dragon with very little noticable difference other than they will not last as long. I'm pretty sure the shoulder angle on the 080 is less than the 115, 26 degrees vs. 28 degrees.
The 122 belt is the same dimensions as the 115 belt, it's made by a cheaper process and it is the stock belt for most if not all of the flatland 600's. As far as I know Polaris doesn't put it in any 800 machine from the factory. My dealer recommended carrying it as a spare belt.