I'm kind of indifferent about this one. I have naturally oily skin - I'm a 6-times-a-day-or-more blotter - so I had really high hopes for this product.
The key on this one is to use a REALLY thin layer. Too much and it'll just slide off your skin, especially oily skin, and take all your makeup with it. It's a little hard to get a good, even, thin layer with the sponge, though I didn't have any better luck with my fingers. I think I'd like to see this product in a serum form, rather than as a puck.
The sponge also starts feeling gritty REALLY quickly. I recommend washing it with soap after every use, or just dig out some product with the back of your fingernail and apply with your fingertips instead.