Heck were still racing @ Holly Springs, Ms > Cmon down ya'll...lol
They're having a three day big money race coming up Thanksgiving weekend.
As far as air verses NX, I prefer air mainly because it's free.
I do like the above mentioned method if needed that is usually its dead on after I cool the car down - But if needed I'll top it off a little on the high side and set them right before I go up to staging, oh and I don't use my generator to run an air compressor, I use that for my battery charger. I do use a air tank though $20 at harbor freight, 10 years and counting.
I highly doubt that you'd benefit any going to NX but it might make your ego feel better toting around that cool looking high pressure bottle & regulator along with your fancy tire pressure equalizing set-up. JMO >Cp