What is the favored air compressor to carry?

I did a lot of research into my compressed air needs and finally went with a small nitrogen tank. The tank holds 40 cu/ft of nitrogen at just under 2,000psi. According to my calculations, using a step down regulator I have enough nitrogen to totally fill at least 4 of my rigs tires to 70psi, enough volume and pressure to run an air-impact wrench long enough to break a seized nut loose and I can easily lower the pressure enough to safely blow out my water lines. When I run low I can exchange the tank for a full one at a NAPA auto parts for $17. It doesn’t take up much space, it fills tires fast, and there’s no compressor to break down.