What's any benefit of it?
You don't need to see map better, because you already know all its geometry if you learned the map, but it's more comfortable to have a good contrast between (bright) enemies and (dark) map. Also, fullbright makes perception of perspective harder because there's no shading to help your brain. Map is just background, it should not distract your eyes/brain from important stuff like players/items.
cg_filter_angles makes it so your view "camera" takes its time before updating to the new position and puts some smoothing in between.
Say you move the mouse 90 degrees to the left, normally the 'camera' would follow the view change instantly. With cg_filter_angles set to say 300, it will take a long while to adjust the view between your previous position to the new one. It will turn very smoothly towards it but take a comically long time.
Considering that it separates the view camera from the direction the player is facing, what you see may not be where your position actually is until the camera gets there. At real low values you can use it as a mouse smoothing feature, I'd say you shouldn't go higher than 1. Stermy's idea of using 0.03 is quite clever.
I occasionally put this on because sometimes when online under lagged conditions I get in the habit of hitting the attack button 'too soon' say with the rail. With filter_angles on I think that my crosshair is not yet on the enemy so I give a couple ms and sometimes I will hit a lot more shots just because my 'view' is working a bit better with the actual visual latency of the game/net latency.
He saw posts by OSEF, THE FRAGGERRRR ))), Heartless, and realized, that even if he lobotomized himself, he could never be, even pretend to be, as dim, dumb and inane as them.
This would ruin any lesser man, i'm suprised he still didn't /wrist.
"I am a certified psychiatrist, and I am looking for a place on the web where I can submit content (or possibly a website) that will help me to become fashionable."