I've used it and never really found anything so special about it. Really and truly, all you need is the blue stuff thats $.99 a gallon. If you want more bite, try a wash booster like P21S but having tried all of the special washes myself (De Icer, Bug wash, pink, red, green, purple, polka dotted) nothing worked as well as just plain blue no name brand.
Plus the dyes in some of them will drive you nuts tracking down stains.