Waterproofs and softens leather well. Makes it a lot easier to wash off salt and sand during the winter, and keeps my feet dry (and therefore warm). Darkens the leather up a bit, but I actually like it.
This would be five stars, but the Amazon description says it's 5oz, and the picture says 2.5oz. If it were 5 oz, it'd be a good deal. At 2.5, it's overpriced. Stupid me didn't check it before I opened it up and started using it, so I'll be keeping it. But when it runs out (which shouldn't take long, at 2.5 oz), I'll be buying a different product.