>>303628061
MP5 is still decent and is more reliable for fast kills than both of those. Bizon is just flat out overpowered for the price though. P90 is trash because of Dave's recoil mechanics for it but it's also been powercreeped by buffs to the other SMGs; Complete waste of money at this point. 
Revolver could use a price reduction now since nothing can be done about the ammo count.