So I was thinking, "Hey, maybe each turret shoudl have its own stats" add a bit more diverstity and remove the linear upgrading process.

Maybe: Light turret: faster deployment, faster turning speed/tracking, less damage, lesshealth
Medium: Middleground turret
Gatling: Slower deployment time, slower turning, higher health, higher damage

I dunno, see what you think

i agree to this but im also okay with it not changing at all

Buffing the turrets is a huge potential problem. Turrets, used by people that understand how to use them, are solid now. If you buff them, the people that are bad with turrets now will still be bad, but the people that understand how to use the turrets will be exponentially harder to deal with.

Would have to change the ability buying if they weren't linear. At the moment they're just firing rate upgrades and the Gatling is balanced by having to spend three ability points to have it.

I've only played an Engineer since release, and I have to say turrets don't need buffing. They're already reaaaaal good, if you set them in the right places. I would like to see individual changes in turrets though that really set them apart from one another, and allow even the light turrets to find use in high-level play, instead of Gatling being the only way to go.

I think it should be an upgrade process.
Light < Med < Gatling

But I also think the 'buff' should be applied by Opperatives and not some patch. To make them more useful as a class, and the turrets more useful.
Instead of the "Control Turret" ability (Which is actually useless), the Opperative should be able to buff the turret.

Maybe the buff could increase the targeting speed, or the swaying speed at which the turret looks around.
This buff could also maybe be applied to MG Nests? Possibly make it's rate of fire increased and the rate at which it overheats slower.

The Opperative would gain EXP for buffing the turret, and gain EXP when that turret attacked and/or killed an enemy.

I think this is a good idea - not the part about the MG Nest though (since that already has a real player and it should be their fault if they cannot fire correctly on a powerful gun. Turrets are hit or miss based on how the tactful the player is and where on the map it is placed.
I agree that the turrets are very good as is damage wise, however I am open to the idea of an operative buffing the health of a turret (since I do not see why so many people complain about how turrets are unfair; just destroy them like I do or have an operative hack or throw an EMP). I think there is enough that works against a turret to make it a little stronger or quicker in finding targets.