Basically making sure that you're not having the engine draw too much of the level at once (ie: being able to see/draw the enemy flagroom from your own flagroom is bad)... it affects FPS negatively and it really makes the video cards cry. So take VIS into consideration before submitting your map, because again, we don't have time to unfuck them before we release v3.5.
PS: Static loves me =
=V3=