Doesn't matter how you gain speed, it can be double-tapping buttons instead of strafing, no problem. But I will never play a game where I can't preserve the speed I gain (again, no matter how - can be jumping or gliding or sliding or whatever).
I'm sure there's nothing wrong with it but saying that is "hard to master" is a joke since the moment in the first 10 minutes you learn it it's also mastered.
Still, some people like it. Strafe jumping is hard to learn but to me the toxikk movement looks like jerky dodgy crap.