The UMP45 as you say is good though, I think underrated also, as you say quite controllable, I do remember specifically using that on Sanhok which a lot of the time ends up being quite close quaters in and around those rocks, basically killing like 3 people in a row with it at pretty close quaters.
I think the MP5k on the maps it is available is the king when talking SMGs that thing fully kitted is a laser beam, it obviously does mean you need to get the tac stock for it. I dont like the vector so much, although playing on Erengal the other day fighting in a city with a completely unmodded Vector, the first few shows are surprisingly accurate, tapping fire for like 2 - 3 rounds at even like 30-40 m and landing a couple of shots at that range.
I am trying to get better with sniper rifles now though, I have never been good at sniping at FPS games, even back in the original counter strike, I think there is a certain mentality to using them, I find if you shoot and miss, they turn around and nail you with a DMR, or land a body shot, they hide, heal and end up doing the same, but.......If you can land a headshot its a knock which puts a team under more pressure, and I am getting (a little) better at it, I need a lot more practise though, but at range I am finding against a skilled player unles you really catch them in the open, the DMR's just dont have the power to knock fast enough before they can grab cover/heal, and you end up in a longer engaugement, and then get third partied etc
Ill keep an eye out what name do you use in game?