They are nice for anything small you would like cooked faster than a conventional oven would, but wouldn't want to microwave, in order to keep that baked outer crispiness like french fries, corn dogs, etc. All they do is circulate super heated air through and around the food. It's basically a more efficient convection oven. They are also great if you have some fries from a restaurant that have gone soggy. Toss them in for a few minutes and they will be crispy again.