The PDK of course...but the manual is much more fun and involving. You win some, you lose some. Guess can't have it all.

 

Guy who autocrosses here on his '07 gt3 rs did it several times with me on passenger seat - car 'kangaroos' a bit at start but then his rear hoosiers are at right temperature and yes, car goes off like a rocket.

I think by doing it regularly you will simply get 1st gear totally damaged or one of gear teeth broken off like on Ian`s car - and keep in mind - after damaging 1st gear you will need completely new gearbox as 1st gear teeth are is not replaceable.

You can do essentially same technic with 3K RPM at start and it makes much less damage to car with essentially almost same result. Plus on PS2 tires it seems they melt a bit after such rocket jump start with jumping and feel like a butter for first 50ft or so - so you essentially loose time instead of gaining it. At least on my car it was feeling so so I stopped trying to start from 6K RPM.

And I do not even want to think what does it do to clutch and flywheel.