I have the ARB dual compressor as well. I air down to 12-18 psi depending on the terrain but I only take my tires back up to 36-38 psi. Anything over 40 psi on these trucks with an E-Load Range tire would be brutal. The compressor is hot after airing all four tires up so sometimes if I am not in a hurry or in inclement weather I will let it rest for a few minutes after doing two tires before I finish the others.
The PowerTank is a nice option, it stays ice cold when in use, airs up quickly and it's a nice option for running air tools, but they run out of CO2 quickly and then you'll spend $15-20 to refill it at your local welding or paint ball store. I got tired of having to take it by to have it refilled and they take up a decent amount of space inside of your rig as well. The 33's on these GX's aren't that big so it should last longer than it did with the 35's and 37's that were on my Jeeps back when I used mine, but it's still an added complexity that you must keep track of as it would suck to run out on the trail when you need it to get back home.
The PowerTank is a nice option, it stays ice cold when in use, airs up quickly and it's a nice option for running air tools, but they run out of CO2 quickly and then you'll spend $15-20 to refill it at your local welding or paint ball store. I got tired of having to take it by to have it refilled and they take up a decent amount of space inside of your rig as well. The 33's on these GX's aren't that big so it should last longer than it did with the 35's and 37's that were on my Jeeps back when I used mine, but it's still an added complexity that you must keep track of as it would suck to run out on the trail when you need it to get back home.