Growing up my dad was a judge and had some interesting toys. This included at one time a 1928 thompson, M3, mp40 and a c96 30 luger select fire broomhandle.
The Thompson is cool, but feels like it weighs as much as an m1 but still has terrible climbe even with a cuts comp. The m3 is a bush beater, if a bush moves, mow it down. Sights were better on my Red Rider bb gun. Although not on the list or realy fit, the c96 was my fav! Riiiiiip! Esp with the shoulder stock!
For this discussion the mp40 is just great. I can not say about battle conditions, but you could write your name on a wall with it.
I have never shot a sten, I've been told it is on par with a mp40.
Dad's older brother was in in Italy in WWII and claims all the italian auto weapons the 38's and the 34 pistols were so so.
I would love to shoot a ppsh. If I got the chance I would bet it would be my pick. the 7.62 is a nasty little round.