How will these two tracks mount up against each other in the deep snow and on the trails? I know they both end up having similiar footprints as far as square inches goes but what are the pluses and minuses to each?

Its quite a bit easier to get a shorter track leaned over and turning when your in the deep powder then a real long track. I'm not sure on as little of difference as a 136 to a 144 though, thats only 4 more inches on the ground.

Jump in and swim.all around go to a 144 x 16 and have fun...will handle no different and will float like a boat ! I have a 144 rev and a 151 summit rev. Both are very good just the 144 is easier to roll over and bang out a tight corner . I do prefer the longer track but i mostly ride mountain terrain.