How Good is VAC

Well it's quite shitty anticheat, that's for sure, even EasyAntiCheat will be good with its job I think.

You can ruin the game for several days by playing with cheats without stopping, until the complaint from your first bwoinked round in competitive mode is checked by steam investigators or someone like that. To be honest, even split play doesn't help, and making the game free was a mistake.