I have used both, and I like both, but the Colorstay is so much less expensive, and I know the color I look best in, so I buy Colorstay. I think that one application is best, since you are suppose to work on one quarter of your face at a time, so that the product does not dry before you are finished blending. I prefer a sponge, but the Estee Lauder people use a foundation brush, and said they thought the sponge wasted too much product. I find the brush takes longer than I usually want to spend, and for about 1/3 of the price, with the Colorstay I can use a sponge and throw it away, rather than have to carefully clean a foundation brush of water-resistant foundation.