I had a PowerTank and after a few years (5 maybe?) it needs to be inspected and the welding shop I use wouldn't fill it and didn't have time to do an inspection right then. Eventually, it will need hydrotested as well. I started just swapping tanks there and now I don't have to worry about tank inspections or quality or anything, just drop off and grab a full tank. Literally the only downside is it is silver instead of black. I don't see a reason to buy one.
That said, I HIGHLY recommend one of the
PowerTank inflators. I went through a bunch of cheap ones from Amazon and the high pressure just blew out the gauge. I've used a PowerTank one for a couple years now with no issues.
I'm 99% sure I have a 10lb tank you can have if you want to pick it up. I can't be bothered to ship it. You would still need regulator, hose, and inflator though.
EDIT: I just google'd and every 5 years the CO2 tank has to be hydrotested. It just isn't worth messing with when you can find a place that'll swap tanks.