This is a mod that aims to rework the Sentry Turrets and make them work on DS/OD

The first change was to the first skill in the skill tree.

Now there are 3 reworked and renamed skills 
"DEFENCE UP!" Instead of Third Law
BASIC: Sentry deployment cost is reduced by 5% and will mark special enemies (The synced mark can be disabled from the mod options menu) 
ACED: Your Sentry Gains a protective shield and marked enemies get more damage.

"IMPROVED ENGINEERING!" Instead of ENGINEERING
BASIC: You auto-pickup a broken sentry. You can now select a less noisy version of the sentry guns, making them much less likely to be targeted by enemies.
ACED: Same as ENGINEERING Aced

"ANGRY SENTRY" Instead of ECO SENTRY
BASIC: The cost of deploying a sentry gun is reduced by 5% When your sentry gets destroyed the resulting explosion deals 400 points of damage.
ACED: Your sentry guns gain 150% increased health. When your sentry gets destroyed the resulting explosion deals  750 points of damage

And a brand NEW SKILL!
"LESS IS BETTER!" THIS SKILL CAN'T BE USED WITH TOWER DEFENCE! (Yes I found how to disable the point invest :P)
BASIC: You can now carry 1 extra sentry gun.
ACED: Your max amount of sentry per each equipment slot is now capped at 2. But the AP rate of fire malus is now reduced by 40% (So instead of -75% is now -51%) (Some cool stuff is coming for this skill but now I can only offer you this) (Check the "Upcoming" section to read how this skill will change)

It also includes the Sentry model from the firecrest mod to remove it just delete the folder units inside the mx_sentry folder

https://bitbucket.org/mxswat/mxs-sentry-rework/src/master/

I suggest to use also these mods it allows you to place the turret everywhere also on walls!:
Symmetra
Pick up all sentries keybind

I suggest you use this awesome build

Upcoming:
Fixes. Code clean up
The less is better "aced" version will be changed with an option in the menu that when you unlock the skill will allow you to choose your buff
One between:

• AP Rof buff.
  
• Mini HE round.
  
• Tactical Pulse.
  
• Scrambler.
  
• Particular ammo types. (fire, shock, poison, feedback, emp)
  
• Sniper turret, -80% RoF, +200% dmg and 100% accurate? thanks to @Xx-Nelson-xX
  
• Your own idea! Propose it in the comments!
  

Requires BEARDLIB!