Crappy tire to start until you really think you need serious air.
Engine driven is not very practical on a TJ. The serpentine system creates a lot of headaches. Its not the same thing as throwing together a v belted system.
Viar, extreme air, and several others are good electric systems, but shouldnt be considered until you really think you need considerable air.
Jeeps being as small as they are, you dont need any more then 18psi to safely and comfortably drive yourself home, or to a gas station after wheeling. Without beadlocks you probably arent wheeling with less then 12psi.
6 psi a tire is pretty insignificant, even for a crappy tire compressor.
The caddy ones are cheap and reliable, but really arent much faster then a crappy tire unit in my experience.