Pros: Nice complete unit - I got the 15lb tank. Fairly easy to mount. Up to 7 four tire airups - more than a month or riding for me + air tools + welding gas!
Cons: Need to refill at about $15/tank - find a place that will "top off the tank" periodically at a pro-rated price. Once you hit 500 lb - start looking for a refill.
Comments: I first considered a tank/compressor system. There is just no room under a JK for a tank. I went with CO2 because I can also use it for air tools on the trail and for welding in the garage - multi-use system. I mounted my tank on the driver side in the back of the Jeep on drivers side - it blocks access to the tool tray cover, but then I rarely get in there as all my trail stuff is in my boonie box. Sure makes airing up a breeze! 35 seconds per tire to go from 12 lb to 32 lb and I get up to 7 air ups per tank.