M4A1 vs. K2 vs. AUG vs. FAMAS for GM?

I like using my Ruger and all but it comes up short in some departments. Just some slight mods to it, sacrificing damage for basically everything.

Now the list below is only slight tweaks, not omgzor god mode plox, mods.

Faster rof / reload.
Slightly less weight and recoil. (the recoil isn't a problem to me, because I know how to control it, just would like a quicker return to normality so transitioning to new targets is more fluent.)

I have compared these guns and well they all pretty much meet the standards I am looking for.