I hate how ballistic vests don't protect you from pistol rounds, and how all SMG's fire through materials better than any other gun other than snipers
I just hate the unrealistic aspects of all the guns really
oh and the P99 is better, it shoots faster and deals more damage at close range, which is stupid because it's a 9mm and the USP is a .45. I love the P99 anyway lol. My favorite gun is the ACR with extended mags and an underswung shotgun, with an XM25 secondary