All race genres use nitrogen, and they don't even bother to use air for the in-built jacks. They were using 25 years ago when I was a timekeeper for the saloon car race in Wellington.

It conducts heat better and can distrubute the heat and dissipate it better, it is about half the weight of air and therefore reduces unsprung weight which for racers is far more important than any weight savings on the total mass of the car. It allows the suspension to work better, stick to the road quicker.

So if you plan any sporting journeys - go for it. Otherwise you still have to keep a tank of it for tyre checks.