The Uzi can be found in the level Payback, both lying on the ground, in the clearing that Mason lands the Hind and in the hands of a few Spetsnaz troops at the entrance to the POW compound.
The Uzi performs exceptionally well at close range, especially while hipfiring, and/or adding a Grip. In most cases, it beats out the popularAK74u at close range. Because of its amazing hipfire abilities,Steady Aim is preferred, but Sleight of Hand is a good option with it too, as the reload is awkward and a little bit slow. Compared to other similar submachine-guns, the Uzi has a high magazine capacity, but also extremely high recoil (the most recoil of any gun in the Multiplayer without grip).
A Red Dot Sight or a Reflex sight could also be a good choice, as the Iron sights can be very obstructive to many players. However, recoil with the Uzi is such that there is almost never any point to ADS, making any sort of sight attachment something of a waste. On the other hand, with Warlord, using a sight in conjunction with a grip can benefit greatly, eliminating higher recoil and obstuctive ironsights.