I wanted to try this foundation out for a wedding I was attending because I heard it's a good dupe for MAC Studio Fix Fluid. I ended up buying the Combo/Oily formula (after swapping it about 3 times to get a decent color match). Here's the long & short of it:
+ Medium to Full coverage
+ Stays on all day (make sure you have a good makeup remover!)
+ Did not break me out
- Would prefer a higher SPF
- Not enough shades w/yellow undertones (Buff is a bit too light for my skin but Sand Beige is a little dark & too pink)
- Felt a little heavy on my face
- Did not control oil well
It does tend to dry fast, so you need to work quickly. Due to lack of color choices for my skin tone, I most likely won't be buying again. If they carried more Asian-friendly shades, I'd probably go back to it. But it is a great product and if you find a matching shade, it's performs well at a price that's practically a steal.
EDIT: I was looking to possibly try Colorstay again, but I noticed that one of the ingredients listed for the foundation is retinyl palmitate, which is currently being looked at due to the possibility of it accelerating cancer in lab rats. While I'm not 100% convinced, I try to avoid it when I can unless there is conclusive evidence saying otherwise. So if you're like me, you might want to stay away from this foundation in the meanwhile.