This is the best thing I ever bought for paintball. Easily get a day's play of refills for at least 2 people with air left over. (each consecutive fill is slightly less in psi)
Also I have been seeing posts and receiving PM's about HPA. Some observations:
-Scuba tanks have their own valve configuration. If you want to use it, you will have to get a yoke adapter like the one reviewed here or something similiar.
-Scuba tanks not only require hydro tests but yearly visual checks as well. (another fee)
-You cannot fill scuba or paintball tanks with a generic shop compressor. It requires a 2 stage (or comparable) compressor capable of reaching high pressures; 3000-4500 psi.
-Filling guns with scuba air is cleaner than paintball compressor air. (because it's for breathing)
-If you are unsure of what you're doing, leave it to a trained pro like an airsmith. Don't jerry-rig backyard/garage stuff together. This is no place for ghetto mods; HPA CAN KILL YOU! It can generate schrapnel like projectiles because of the extreme high pressure it's under.
I hope I have helped some out there, and good luck Paintballing in your neck of the woods.