My experience from last season on intakes. I had purchased a used/demo Timbersled ST with TSS. I mounted it up to a 17' 450sxf. I ran the TSS snorkel intake for most of the season. With a little ABS shrouding and trucker tarp, I was able to keep the intake happy on the light blower powder days.
After some time with my PR2 ECU, it was recommended I modify things to go back to the stock intake. Right around this time I found myself riding in snow that was numerous densities and moisture content. The TSS intake became inundated and performance suffered. I had bushings made to flip the TSS shock, and modified a new factory air box. Removing minimal plastic, resealing the hole, and sealing all factory air intake ports was completed. I then installed numerous snow blocking inlets to both sides of the airbox. The inlets were part of a Ski-doo engine venting kit. This resulted in cleaner and more power throughout the power band and never had a intake issue again.
PR2 has dyno proven numbers of the stock intake vs TSS snorkel. I'm guessing the length and shape drastically affect power.
Here are a few pics.