I'm gonna defend Ron on this one. The Thompson just seems, well...easier. I've seen guys jump around a corner, bunny-hopping, and let loose a wild spray of rounds and headshot three of us in Tank Alley. I've used the Thompson to hold the Hotel in Flash (think that's the correct map). I felt dirty afterward and have not done so since.
Sniper seems a little easier to me also, maybe it just my prefered playstyle. Sniper is powerful though, else why is it limited to just two kits per team?
I am NOT calling people that prefer the assault kits skill-less noobs (I hate online jargon). If you like the Thompson, ENJOY! Still, my personal feeling is that the BAR and the Sturm are much more difficult weapons to use properly. You have to know when to move and when not to. They are very difficult to fire accurately standing up and they lack the accuracy of the KAR and Garand (which I just cannot seem to wrap my head around).
p.s. Ron is a monster with the BAR, but he does force me to improve
p.s.s. I stole some moves from Ron, followed him around for about 30 minutes :O