I have my own Nitrogen bottle and have all my rolling stock's tires filled with Nitrogen.

I have an aviation background where Nitrogen is used for a lot of things, but here are some of the reasons to use Nitrogen in the tires.

Yes, it is dry, no moisture.

It is inert so there is no oxidation of wheels,tires, valve stems or the steel belts in them.

The Nitrogen molecule is larger so tires stay inflated to proper pressure longer and is more pressure stable. This can insure the best gas and tire mileage possible. My X5's tires stay at the proper inflation pressure for over a year at a time. Compressed air leaks out of tires about 1.5 lbs a month causing a risk of running under inflated.

Nitrogen inflated tires run cooler which may add to the tire's life.

Nitorgen does not support combustion.

Topping off with compressed air is not a problem if good clean dry air is used. They say the benefits of Nitrogen are not increased in concentrations above about 96% though pure is better.

I think it is worth it, but I was already set up with the bottle and regulator.