I've tried it, but I'm still making my decision about it. I got it b/c it was on sale at Walgreens for like $8 (normally $11 or $12). The only thing I'm not liking so far is the formula. I like ColorStay's formula so much better. But as far as the shading goes, I'm still testing it out. I was told I could bring it back for a refund if I didn't like it, so I'll give it another try to see if I'll keep it or not.
Oh, and I just wanted to add that the whole chamber thing is a pretty neat idea. It's relatively easy to use and it doesn't get messy. You give the bottle a couple of pumps based on the shade selection you've chosen and out comes a mixture of a light and dark shade of your skin tone. Since I used ColorStay's foundation in Caramel, I'm still working on finding the same shade that comes close to it. But overall, it's a pretty neat idea. I'm just still trying to make up my mind about the formula.