After hearing countless beauty gurus rave about this product I finally picked it up. I was unsure which shade to get but then decided on transparent (because who can go wrong with that?).
This powder has a very nice formula which you can build on if you need. I tend to stick to one small layer since too much of the transparent shade can leave a bit of a white-cast. The powder is great at giving a nice matte finish to dewy foundations and oil. I really do think this powder effects the longevity of my foundation. I use this powder when I play sports (you shouldn't wear foundation when playing sports) and I need the coverage and it makes my foundation/BB cream last.
I would definitely recommend this powder to anyone who has oily skin/foundation that's too dewy for their liking. This product is the best drugstore powder I've tried (and I've tried a lot).