Thanks a lot! I did NOT experience any lag, and Kaspersky said no viruses. You can only see the enemies near you behind the walls, but it is totally worth it. Sometimes it only works when they are really close, but that seems to depend on the game mode and map, because other times I could see them reasonably far away.
I played about 30h with this and did not get detected (on VAC-enabled servers).
Today there was an update, I didn't test it after that. Anyone?
btw may I ask how was it made?