I have been using this shampoo and the coordinating conditioner for almost two weeks and I am VERY happy with them. I have the average amount hair, but each individual strand is fine and my hair tends to get oily, so I am always trying to get more volume into it. It took a few days for my hair to get used to the shampoo. I should add that my hair is all-natural, no dye, highlights, or chemical processes whatsoever.
I agree with other reviewers that it does feel remarkably different compared to the drugstore brands most people are used to using. At first, I tried to use as little as possible because it costs twice as much as a drugstore brand, but now I'm fine with using as much as I need to cover my whole scalp because the benefits definitely outweigh the costs. Because my scalp gets so oily, I just use the shampoo there and let it rinse through the rest of my medium-length hair and this seems to work just fine.
I'd say this shampoo is very close in quality to a salon-brand shampoo, but doesn't cost nearly as much. And I love the way it smells - even my boyfriend said my hair smelled good! I'm not quite sure yet, but I think this product has improved my dandruff, which is definitely an added bonus!