The Sharp Shooter Mobile Anti-Missile Defense is a UEF land unit. It is also a great defense unit. This unit can shoot down incoming tactical missiles but a large amount will overpower them so build plenty to make sure your base and armies are safe.
Since tactical missiles don't track targets and are more often used against enemy structures, Sharp Shooters are more often relegated to defending a base against tactical missiles than actually placed with a strike force. However, a handful of 5 of these will do the job quite nicely, so if you are sending a strike force of 50+ units (where, at close range, a tactical missile fired at the front of your group will still probably hit the back of your group) then a couple of these mixed in is still a good idea. They are also a great idea if you are playing in a close-quarters match because the Illuminate Tactical missile launchers are devastating against structures and have a great range too.
It should be noted that the Sharp Shooter is useful as an escort unit for slow units with siege capabilities, such as the Fatboy or Jackhammer. The Sharp Shooter is the only way to defend a deployed Jackhammer from tactical missiles.
The Sharp Shooter is technically superior to the Sliptack as it possesses more health, DPS, and faster health regeneration. Unfortunately, the Sharp shooter is surprisingly far up the research tree and not accessible very quickly. This does ask a question why it is higher up the tree than it's Illuminate and Cybran counterparts. Shield upgrades do not apply to the Shap Shooter.
This unit works almost identically to a Tactial / Nuclear Missile Defense blocking tactical missiles, in the sense that it fires lots of little lasers per second at the missiles, which is a great way of defending itself. Combine it with some P-Shields for a great defense force for your base or attack force.