I have a semi-auto legal version from Auto Ordnance....a heavy shooter, for sure and it can shoot any kind of crap 45 ACP you can feed it. I’ve shot an M1A1 full auto with the 12” barrel and I loved it.
The only drawback to the legal version is the 16” barrel and that it (and the M1A1) wouldn’t accept a 100 rnd drum magazine. But overall, I think it’s the best of all of them.
A real M1A1 Thompson only shot 20 or 30 rd magazines. The firing pin was cut into the bolt which is a 2 lb (a guess) bolt assembly (a big ass bolt) that flung back and forth. Basically a slam fire operation. It’s heavy for sure, but not in the 50 lb range.