I'm not a frequent user of any of them, so I'm sure there are others here with far more subject matter knowledge than me--but one thing IHeart has that the others don't is access to a significant array of terrestrial stations. If you're a fan of station which is local to you, but will be traveling outside of its terrestrial broadcast area, and if it's an IHeart station, you can still listen to it via the internet using a computer or mobile device if/when you're traveling. Granted, many individual station websites now allow that too--but this brings them all together in a single source.