This is something I've always wondered with the cover screen that Gunslinger/Snipers get. When I drop straight into cover screen/crouch on the spot... people like to try and run around 'behind me'. Like it makes some sort of difference. Which from everything I have seen in taking damage, survivability, and dishing damage... it does not.
Even though the 'graphic' is in front of you, it seems to still give you all the benefits of cover even to enemies who are attacking you from behind. However taking hard cover (behind an object) it DOES make a difference if an enemy comes around behind you or not.
As a side note, when you drop to cover screen, they cannot break Line of Sight by simply running to behind you (you turn and shoot them either way).
Be curious to get any sort of official word on "Does cover screen still protect you from rear enemies?"
I'll gladly clear this up for you. The official word would be this:
There are two major benefits from cover (in addition to various skills on the Gunslinger/Sniper that make cover an integral part of their gameplay).
(1) People cannot hit you with most ranged attacks while you have cover against them (as in: you are crouched behind an object that breaks line of sight). It does not matter if you used 'Take Cover' or 'Crouch' to get behind the object, the net result is the same. This benefit is available to both the Sniper/Gunslinger and the Scoundrel/Operative and players that remember to take advantage of it can avoid a lot of incoming damage, at least against ranged classes.
(2) Cover screen and Hold Position on the Sniper/Gunslinger Advanced class.
This is a passive ability granted at level 10 upon choosing this advanced class. It creates that small energy shield in front of the player and gives them a 20% ranged defense boost against attacks from any direction.
Ranged defense is used to determine if a target can hit you with a ranged weapon. The higher your ranged defense, the higher the attacker's accuracy must be to compensate. The bigger the difference in your favor, the more likely enemies will miss. (It's a common misconception that 100% accuracy means you hit 100% of the time.) Other factors such as level difference, etc. also come into play of course, but that's it in a nutshell.
Additionally, hold position makes the character immune to interrupts and ability pushback (i.e. activation time increasing when taking damage).
Benefit (1) can be cancelled by simply walking around the target and shooting them in the back (or using melee attacks)
Benefit (2) is active 360 degrees around the target and requires your target to knock you out of cover to be cancelled.
Hope that clears it up.