SOLDIERX.COM Nobody Can Stop Information Insemination

i want to get this communities opinion on system optimizers. my first question is do they actually do much? they say they delete empty registry keys and the likes...but do they actually do this? i have used Advanced System Optimizer (http://www.systweak.com/aso/) and it never really seemed to speed up my computer. but maybe it actually is doing something under the hood.

are they worth the hassle of installing and using?