All flak frigates have reduced accuracy against strike craft. The targeting uplink translates into a full DPS increase for taking out fighters and bombers, no matter what system you're in.
The range increase is useful on defense to have your starbase outrange torpedo cruisers, and to increase the range of your gauss defenses. This helps to create a stronger overlapping field of fire.
Range is useful on the offense so that your orgov's can outrange starbase abilities. With the LRM upgrades, you can even outrange starbase long range weapons to boot.
Accuracy gives you a clear edge in special sectors which have accuracy penalties. Take full advantage of these sectors when making a choke point.