/\ is a little extreme
its bad for your clutch obviously, and the drive line, but a better observation is that its an extremly inificent way of launching your car. a stock WRX dosent have enough HP to launch efecticly off the line witha clutch dump even at 7K rpm.
the fastest way to launch yer car off the line is to slip the hell out of it.
usualy, ill release the clutch about 50-55%, which is usualy about the first 1/3rd of the friction point on the clutch, instantly, and quickly but smoothly slip it the rest of the way out
if i feel the need to launch ill usualy do it at a lower RPM then most, 3,500 or 4000. some people do it from the 4,000 to 5,000 range. but this is my daily driver, so i like to be nice too it.
once you break the 300whp barier you will have removed all bog-down that will occure with a clutch drop.
i have seen many posts about how burly the stock clutch is, and im sure you will see some crop up in this post shortly. regardless of how good the clutch is, its not good for the clutch or the rest of the drive line to drop the clutch (think about the mechanical aspect of it for a second).
i prefer to exploit the design pros of the wrx, which is its handling and stability on and off road. not its 1/4 mile times.