I've been having issues even on low quality settings on a decent computer (with an NVIDIA GTX 970m 3GB, 24GB RAM and an i7 processor) where the game occasionaly freezes from 1 - 5 seconds.
It seems to generally be when something in the game is updating, like moving to a new area, or enemies loading in. I believe its more due to how the game works, code wise, and the optimization for graphics, than anything else. But this is a very annoying problem that occasionally makes it impossible to play and often gets me killed.
Overall the game is fun to play, but this can really kill the mood and it seems to be something that could be fixed with some optimization.
Hope this reaches your ears, developers, you're likely already aware, but this is what I find to be the biggest issue with the game at the moment. The other things seem to be small tweakes that can be added and fixed later, like the BOT difficulty etc.