Last time I checked, nitrogen followed the same set of physical laws as air, which is, after all, mostly nitrogen anyway. Sounds way too much like a gimmick to me.
PV=nrT (although neither air nor straight N2 is an ideal gas, it is close enough)
I definitely see temperature and pressure issues. I live at 5700 feet (80% of sea level pressure) and typically fish above 10,000 feet (~65% of sea level pressure), so the (over)pressure difference in a toon bladder is substantial. I always make my buddy John deflate his tube a bit before we leave the house, and he always says "Oh, it won't matter much", and I make him do it anyway. We get to the lake and it is twangy tight...
And it might be 120 in the back of the truck on a sunny day, with the toon coming out of 40 degree water, so it gets deflated when it goes in the truck every time.
I CAN see that using nitrogen instead of exhaled breath, which is what most of us end up putting in our tubes and toons at some point, would prevent buildup of moisture inside the toon, along with all the other stuff in our breath like bacteria and such that might get icky after a while.
