I am a big fan of MAC Cosmetics and have personally never experienced any major negative aspects from their products. The Prep+Prime Highlighter is no exception.

It is certainly a unique product. I have never seen any other brands produce something so versatile and effective. The price is fair considering the quality of the product and its multi-purpose. The pen-like applicator allows for easy application and it also saves me having to get another make up brush dirty. It is self-setting so it can be applied under or on top of foundation and creates a subtle yet effective highlight. This also means that I do not need to use any additional powder to set it, which is plus because nobody wants a cake-face.
The Radiant Rose shade works wonders with my fair complexion. I use it under my foundation to conceal under my eyes and create a subtle highlight. It also helps to conceal the dark rings under my eyes which I am prone to.

It has lasted me a long time and only ran out after about 7 months.
I cannot think of any negative aspects to this product and I would recommend it to anyone who is looking to conceal and highlight under the eyes.
It is a staple in my make up drawer and worth the money.