Ya know ive been reading up on these for the last couple weeks, trying to figure out what i want to do.. ive been riding my 153' '12 cat hcr for the last two seasons, and its done nothing but good things, first learners sled I guess that i was introduced onto the mountains with... So now I'm looking to upgrade for next season, and even though I like the cats, my buddy has a 13' Summit X and swears up and down on it, so im wondering, instead of doing the last 2 years on cat and juming to ski doo 15's t3 summit x in a 163, whats changed in cats setup from '12 to 15' that makes me want to stay with them? Any replies appreciated.