Recently, I have been using the Vector a lot, and I have grown to know it's strong points and it's weaknesses. I will also recommend perks, attachments, and other things like that.
The Vector's strongest point is it's incredibly high rate of fire, and lowest recoil of all submachine guns.
Rapid Fire: 9/10
If you use the Vector, you should embrace it's strong points, which in this case are it's high rate of fire.
Everything else, and I mean everything else: 0/10
Do NOT use perks.
Do NOT use secondaries.