Deactivating a robot awards 10 exp points (Fallout: New Vegas only).
A deactivated robot cannot be targeted in V.A.T.S. However, the unit can still take damage, and destroying one will give the same experience and loot as normal. Every attack on a deactivated robot while sneaking will register as a "sneak attack critical", regardless of the player's location or level.
Making contact with a deactivated robot while sneaking may still alert other robots in the vicinity to the player's presence, just as if the robot were fully active.
You cannot disable a robot who goes "unconscious".
When you are given the option to disable a sentry bot, it also gives the option to "talk" to the robot, as if you were interacting with a friendly robot, such as Wadsworth. However, you cannot engage the robot in conversation.
For deactivating a robot using the perk, it is sufficient to be crouched and behind it. As opposed to the perk's description, it is not necessary to be [HIDDEN], i.e. close up and unnoticed. You can in fact charge a hostile robot, crouch, circle strafe and disable it while it is circling about weapons blazing.
Automated turrets are scripted as robots and can be disabled with this perk. While in many cases they are out of reach, ceiling-mounted turrets can be disabled if the player is able to reach them by jumping whilst crouched.
When sneaking up on a robot with this perk, if "talk" is selected, it talks to you and does not attack you. (e.g. A sentry bot, when the talk selection is selected, it will say "Do not interfere with security operations.")
You can reprogram the mainframe in the mobile base crawler to have the security robots attack the Enclave instead of you. There is an additional dialogue with Stiggs where he tells you about this when you first enter the room.