I always have nitrogen refilling on my car tires. I think the major benefit is that I can avoid frequent refilling as it lasts for more than 3 months or so. It gives stable air pressure as nitrogen is less likely to migrate through rubber. So it can ensure consistent inflation pressure which is good for a safe driving. That is why racers insist on having nitrogen than having normal air. Another thing is that you can save money and time as it doesn't need frequent refilling. Do you insist on having nitrogen on tires?
Nitrogen for the tires is expensive here. And there are only few car shops that have nitrogen pumps, most have the ordinary air pumps. For me, the ordinary air is okay since it is being used since the time cars were invented. I think the nitrogen is just a novelty and not really a necessity. By the way, the need to refill the tire depends on the quality of the valve and not in the air or nitrogen. If the valve is good then the pressure will remain for months regardless if ordinary air or nitrogen is in the tire.
I like the fact that it is safer and can be a money saver in the long run. I wish they would sell it here but I haven't seen a single place where I could find it. Even if it's a little pricey safety is first especially for those who can afford it.