The Select SPF 15 by MAC was the first foundation I ever bought and used and it's still as good as new. As long as products perform, smell and feel the way they are supposed to, I keep them.
MAC says: "Our water-based liquid foundation. Combines medium coverage with SPF 15. Provides a fresh, natural matte finish. Layers up, lasts long: helps protect the skin all day. Non-oily. 18 shades. Best way to baby your skin!"
All that is true. It has a very liquid consistence and applies smoothly. Since it distributes so lovely, I usually apply it with my fingers almost like I would do with a face cream.
The finish looks and feels natural and one can get medium coverage with it. The problem with this product is the fact that as soon as it gets hot and one starts to sweat (even only a little) the foundation literally runs down your face..
If there wouldn't be this one flaw, it would be the perfect foundation. So due to this water-based problem I only feel save wearing it when it's cold.
I really like this foundation, but I wouldn't repurchase it. This is a no-go for me, if I wear a foundation it needs to be durable.
Hope this was helpful. There are so many foundations out there, can be quite confusing.