The 50 round drum (L Mag) is boss…
Until you have to reload it. Or carry it further than a few yards.
I much prefer the M1 Thompson. Lighter, simpler, mags are easier to deal with, etc. I rented both to see which I liked better and I’ll fully admit that when it comes to sex appeal, the Chicago typewriter crushes it.
If I had to choose one to lug around the Pacific where every rock or tree has a jap behind it trying to stab me, I want the M1A1 all day every day, any day.