Portable Air Compressor question

I personally own a Viair 400P-RV air compressor. Pricey unit, but 12V and it draws up to 40 amps from the battery. It runs at 2.59cfm unloaded and doesn't slow down very much as pressures rise. it also stops pumping once it hits 150psi and uses a traditional airing gun to fill the tires. Pretty competitive to the smaller pancake filters, just much smaller. Takes a little over a minute to air up my 275/65R20 tires from 15psi to 50psi. Smittybilt makes a 12V air compressor that flows up to 5cfm at lower pressures, but drastically drops as you go over 40psi. That's why I went with Viair. I like to drive on the beach and air back up in little time.