"Firepower" doesn't mean much when the gun doesn't work, the primary attribute of AMTs.
Seriously, very seriously, do yourself a big favor and throw the gun away when you get it back. Don't even waste one round.
As long as the AMT 45 Backup doesn't have something seriously wrong with it (like the one pictured a couple pages back), they can be made to work and work reliably. When you get it to work reliably, it's a good piece. I don't know anything about the new ones coming out - mine is an older one, probably made in the '90's.
The design is simple. They are easy to work on. My AMT came with a factory magazine and an aftermarket magazine. The aftermarket magazine was crap, completely out of spec and simply didn't work. I tried several other aftermarket magazines with my AMT at a gun show and they were all pure crap - some wouldn't even lock up in in the magwell empty! Stick with factory AMT magazines.
Also, if you buy a used AMT make sure that no one has attempted to lighten the trigger. I've heard of people doing this because the trigger pull is quite heavy. It's heavy for a reason - the hammer spring must be stiff to create enough force to ignite the primer. This sounds like common sense, but you'd be surprised what people do.