In this thread, LHF and I agree.
Porting your track was not designed for floatation. Look at a newer set of snowshoes.....don't go there either. That arguement holds no ground.
Snow evacuation(Read zero snow in rear skid compared to full of snow skidframes), rolling resistance(read..single handed pushing, and rolling my sled across a concrete floor with minimal input), and weight loss(Usually between 3-4lbs) are the benefits. If your sled is set-up to benefit, it works great. In our BC powder. Can't comment on...for example Wash concrete. I know WASH guys have complaints about ice buildup in tunnels to the point that tracks have been known to lock up. Never had that issue in BC.......or, I should say, I've never heard of it.
420lb sled with 170hp and a 150" ported track works amazingly well compared to the old 151 non-ported I took off. With a sled that has all the tricks and lightweight parts.....the track, the way I have it, is my best purchase to date.