The K2 is good but it depends on how your gonna use it.
If your spray and pray, this is not your gun.
It's more of a gun to fire in bursts, or taping of one shot at a time on auto or single shot while scoped.
The "burst" mode while useless in CQC is amazing at a medium distance. However it takes a bit of getting used to.
If you find your self sucking with burst switch it to "auto"
Also when you first spawn with the K2 its set to single shot which can be a problem if you walk into a Firefight.
You'll want to change the mode to auto or burst before to go "hunting".
Also you will definitely want to put a scope on it, maybe a suppressor too.
That's all my tips.