Auto nexus...

i use thew autonexus in 30%, is good

Saving you a few times is enough to call it useful already... Where would you be if it hadn't saved you?

Raise your auto nexus %. 20% is low in my opinion - you can lose that much hp fast enough/before the program registers you've lost it and thus it won't "save you". Set it to 30-35% and you'll notice a difference.
I've escaped some O2 shotguns and stuff with <100hp where I would have died had I not used it, so AN is basically one of the 2 things I use client for. Very useful.

40%

I haven't died a single time after raising it from 30%