Second Update 2018----
I have a ton of drugstore powders and this is my favorite one for setting. I love using it with matte foundations because silica is super absorbent allowing me to quickly set areas with concealer using a small amount of product on a brush (I use the Elf Blush brush). Whatever is left on the brush I distribute on the rest of the face. In this small amount, it's almost undetectable but still effective. Using a lot of powder with matte foundations can be a disaster, and with this one you don't have to.
As I've gotten older my tinted loose powders make my fine lines look worse, and if the powder is too heavy (like the Maybelline Fit me powder) it just adds unwanted texture to my skin oftentimes). What I do now is use this HD loose powder to se my liquid/cream products, and then I use one of my tinted powders conservatively, on unwrinkled areas, for the blurring effect. Will repurchase :3
Update 2018 --------
I'm bumping this up to five stars. There is absolutely nothing wrong with this powder. It's translucent and when applied properly close to undetectable. What you WILL see is the mattifying effect it has. From rotating my powders I've noticed this one is SUPER absorbent. You only need a little. It seems Silica (the sole ingredient in this powder) is waaay more absorbent than say, talc.
The best way (and the only way I would suggest) to use this to set makeup, is in a THIN layer. Do not bake with this, you will look super dried up. You also need a soft brush. Most of my brushes are not soft enough and when I go to sweep powder on, they remove foundation and cream contour; you get one of those "where did the coverage go?" moments. So aim for a thin layer and use a VERY soft brush to sweep it on, or EVEN BETTER use a soft flat brush, a velour puff, or a dry sponge and PAT PAT on the powder all over before sweeping softly. To set concealer I use the WET N WILD fluffy Crease brush (white handle) which is amazing for applying a thin even layer of powder around the eye area to set concealer and eye primer, or just any flat foundation brush.
The other great thing about this powder, besides its invisibility act and incredible absorbency, is that its ONE ingredient. A dream for my acne-prone skin. So I tested this powder on its own and it didn't clog my pores. So silica milled to this size is ACNE SAFE (for me). What that means is that I can use this powder to test foundations and color products for comedogenicity, and know FOR SURE, this wasn't the culprit. Which is awesome. I Prime my face with a thin layer of this over my skincare, and I finish my makeup with a thin layer of this which is great for my oily skin without committing the sin of piling on too much of such an absorbent powder. If I put too much my face feels dry and tight, and I have oily skin.
Also concerning shimmer, it doesn't have any. The NYX MINERAL setting powder may have some, but not this one. The mineral setting powder breaks me out, this one doesn't.
I have repurchased already and I would repurchase. The only skin type I would not recommend this to is Very Dry skin. You don't need such an absorbent powder, you need something weaker with less silica, or no silica. Probably something Talc, or Mica based, or even a luminous pressed powder, because those can have oils and silicones added to them, which makes them even less absorbent/drying, something like the Charlotte Tilbury Skin Perfecting Micro-Powder.