The suit has a similar design to the assassin suit, but is cleaner and has a luminescent white chest piece with similar white stripes on the back, possibly circuitry. The suit itself has a built-in medical system that dispenses Med-X and stimpaks automatically, much like the prototype medic power armor of Fallout 3. A female on-board computer narrates the usage and current levels of these items, as well as warning of impending combat situations, reminding the player of an active Pip-Boy light, and making off-hand comments without prompting. The computer is very similar to, and just as talkative as, the personality modules given to the Light Switches in The Sink.
When poisoned by a cazador, the suit will dispense a stimpak if available and cure the poison while also increasing your health.
Upgrades
The suit can be upgraded in the course of four stealth tests in the X-13 facility. Bonuses from upgrades are cumulative.
Firmware version 1.1 - Has a bonus of +10 to Sneak (Stacks with the +15 sneak already on the armor, giving +25 to sneak).
Firmware version 1.2 - Adds a bonus of +1 Perception.
Firmware version 1.3 - Adds a bonus of +1 Agility.
Firmware version 1.4 - Adds a bonus of +20% to Stealth movement speed.
It appears that the creation of the psychoanalytic cardiac-dampening sneaky stealth suit was based on the Chinese stealth armor. This can be seen in the X-13 Testing Facility when one looks at the mannequins wearing the prototypes. However, while the head piece is seen on the mannequins, there is no head piece attached to the suit or as a separate item.
The stealth suit is considered a medium-type armor, meaning you are slowed a bit by wearing it (this slowing effect is largely negated by the bonus to sneaking speed when the suit is fully upgraded). You also have to find other medium armors to maintain the suit with jury rigging or repair it with standard combat armor.
Unlike the prototype medic power armor from Fallout 3, the Med-X dispensed by the suit is regular Med-X, which the player can become addicted to.
Stimpaks used by the suit are not affected by Medicine level.
The suit will be sure to mention any time you are sneaking with the Pip-Boy's light on.
If your health is low, the suit will use a stimpak, and will continuously do this until your health reaches an adequate level. In hardcore mode, the suit checks to see if there are any restore health effects first, if not, it then administers a stimpak.
When unequipping the suit from a companion, it still plays an audio comment as if the player was wearing it.
pcxbox360 There is a bug where after the suit auto-applies a stimpak your health will not increase; keeping your health at the minimum threshold for the damage script. This causes the suit to use a stimpak every time you're injured, as you drop below the scripted HP, burning through stimpaks extremely quickly.
pc Before starting the stealth research in X-13 make sure all armor pieces are in your inventory. Starting the run before the pieces are taken may bug the script and result in not getting the armor.
pc The stealth suit seems to occasionally glitch out, and continuously issue doses of Med-X until the user's supply has been emptied, or until the suit is taken off (Leading to Med-X addiction very quickly).
pcxbox360 When fully upgraded, it doesn't seem to boost your sneak speed by the said 20%.
xbox360 In third-person view, rotating to the front side of your character can sometimes cause the head and arms of the player character to disappear, immediately reappearing once the camera returns to the rear.
↑From Klein's dialogue files - "The psycho-analytic cardiac-dampening sneaky stealth suit, a suit like NOTHING this world has ever heard, seen, or could EVER see!