this stuff rocks!!!!!!! i did`nt think my car could get any slicker or reflective but oid did the trick. the cost alone is worth it, a gallon of concentrate makes alot like four gallons ( don`t quote me ). you mix it 3:1 water (i use distilled) so like i said it makes alot. you use it like any other qd but the result are like i`ve never experienced before. now i have`nt used fk425, which i hear is very slick, but i`ve heard on other sites that this stuff is even better, again i can`t say not having used fk425 or many others, i only know it`s better than anything i `ve used so far. the slickness and gloss is amazing, i can honestly say i urge you to at least try it, you`ll be amazed to, i think.