Respawn Timer
A very useful tactical "improvement", that can be used for killing or arresting exactly after respawn has occured, as well as spawn nading without a fail. It can also help force enemy team spawn into determined places. Respawn timer shows the true time of opponents being spawned, instead of the false time displayed when pressing ESC, which is caused by lags. This modification is almost undetectable; only a picture/video of the user's gameplay (or UAC screens) can show use of it. It can also be discovered in the respective users' .inis.
Video of use of a respawntimer (check the bottom left corner near the bullets area) --> http://www.xfire.com/video/557e1a/
Sound
Modified sound is even more useful than a respawn timer. If can help you precisely discover the true position of your opponent. While you are walking (not running - pressing shift), your steps are almost inaudible. With this modification, you hear your opponent's steps much louder and easier. Modified sound is also hard to detect - it can be recognized only by listening to the audio if its user.
Suspected video of use of modified sound (ignore the fuzzyness, instead listen carefully to the eerie stomps @ 0.25 secs) --> http://en.client.xfire.com/video/4daaa8/
Gas Mask Overlay
Gas Mask Overlay
This modification helps improve your vision when using the gas-mask. It removes the overlay meaning you have the vision that a helmet-user would have.