it actually comes down to looks, the stock springs are ideal fo handling b/c of the ride height, but the car rides VERY high so people lower it...

 

okay, stiffer springs will keep your car flatter in the corners, and on a flat surface will allow your car to handle better. shocks with more compression dampening will also allow your car to handle better on a flat surface. of course there is much more to say on this topic, but if you go to a website like www.vividracing.com you can check out all the alternatives, but I wouldn't recommend buying from them unless you have money to burn because their prices are not exactly the cheapest. they do have probably the best selection of parts on the internet for the WRX however. good luck.