To get the negative out of the way first... the shade range sucks. There are only 3 shades available in the U.S. through Sephora at the moment, and 6 available through Illamasqua's website. As per usual there are no shades for pale blondies.
This stuff is like a brow powder and a pencil in one. If applied with a damp brush, you can get the pigment needed to fill in very sparse areas (Which you would typically need a pencil for -- the outer 1/3 of my brows are painfully insufficient), or applied with a dry brush it will give a soft, natural effect for those who don't need as much help in the brow department. It could even be used to set other eyebrow pencils. Loving using this as an eyeshadow as well, a wonderfully pigmented deep neutral crease shade.
You get A TON of product for the amount you use for brows. I've had this for over a year now and have just barely hit pan in one corner. It lasts all darn day, this has stood up to my super oily t-zone through grueling 13 hour days and still looked perfect!