After the last patch to the server, I have noticed that the turret backpacks are no longer available to any class but the FSG gunner. There being only one slot however for FSG, it really acts more as a removal of turrets. The FSG gunner will always focus more on mortar than players who would use the hmg or gmg, titan AT and AA. I humbly suggest allowing each class a particular turret. For example, the AT soldier would use the TITAN turrets and regular infantry the hmg and gmg. The engineer would have access to the AI turrets as well as hmg and gmg turrets ("Buildin a sentry"!). The FSG slot would retain access to all turrets including mortars. Because the turrets have been collectively restricted to a single slot, their usage has dropped to almost none at all.
The turrets are a particularly fun part of invade and annex and I have enjoyed setting them up at HQs during defense missions. They allow players an option of heavy weaponry emplacements and a whole new way to camp.
As a player who used turrets all the time, I'll admit a little tear rolled down my cheek when the box beefed up and demanded I hand over the backpack. The limitation for mortar usage was necessary, but I think we'd enjoy regaining the use of regular turrets :).