I never saw much of a difference between foundation brushes/sponges/fingertips until I tried the beautyblender. I've used it with my everyday Laura Mercier tinted moisturizer, and also with Chanel foundation, and it makes both of them look ten times better than they ever have before. My face looks almost airbrushed, and feels less dry than with traditional sponges.
Be careful if you live somewhere humid and make sure your beautyblender really gets to dry out between uses. I had one get moldy after I put it back in its case before it was fully dry.