From Supreme Commander Wiki
The differences between the various faction's specific turrets are minimal, but enough to make each turret unique. These turrets can serve early on as defense against armies and later on as an assistant to your more powerful turrets. These turret also work well against close combat units, especially Monkeylord. These turrets are cheap enough to be deploy in huge numbers. With 150 DPS and the same range of many unit, theses unit can be use late into end game. Most Players often overlook this unit when attacking your base, focusing on your economy or your Counter strike units, and when their army enter firing range of 50+ of these pd, you have almost guarantee success in defending you base.
[edit] Factional Differences
The only known difference between the various turrets are the fact that the UEF and Cybran ones turn to face their target (approximately) 33% slower (and are less resistant to kiting as a result).
Cybran
Auto Gun firing at group of
Hunters