When it's all said and done, the only thing better about a nitrogen filled tire is that the systems used to air the tires have little to no water, so you're not putting in humid air. Essentially a compressor with a Dryer system will give you those same results, just a mixed blend of conventional air, which is still 78% Nitrogen by volume.
Nitrogen still seeps from the tire, albeit not as much as natural air; but tests prove it is a nominal difference. If you are checking the tires every month as you should regardless, you won't skip a beat. As far as tire rot, that's caused more by the moisture in the tires then the type of air.
Running cooler with nitrogen...come on...now that's just marketing BS.
In the long run, nitrogen filled tires are best for people that don't take care of their tires, chicks and old people. But I won't pay extra for air in the tires ever. Want to give me nitrogen for free, sure, I'm yer huckleberry...but since my compressor at home has a dryer on it, WTH do I really need nitrogen only for?