I am in two minds about this. It is cheating if you use it in a game where the lack of sights is part of the balancing. Say powerful sniper rifles having no crosshair outside the scope, to prevent them from being hip cannons of doom. Just an example. On the other hand, certain developers fail to understand that the whole point of sights are that they should be visible, and also that not all games are played in a deep bunker on the dark side of the moon. In that case this gadget corrects a flaw in the game.