Obviously the aimbot and ESP are very good in any gamemode involving a weapon and killing other people.
What makes the hack very unique to me, however, are the little details.

For one, you have the ability to ghost (default: homebutton). This is very useful for spying through houses in darkrp or barricades in zombiesurvival. Then you also have the torch for example, which can really help you in games like prophunt or slenderman.

VAC isn't really supported on gmod. You can get banned by various other things though.
I heard of a ban wave made by garry himself, too. Not sure what's up with that tho.