It's great for perception, but on multiple occasions they've almost shut down the recruiting portion of the site. As it stands right now they have little to no funding. Their "scouts" that evaluate not only are severely more depleted in numbers but also don't get eyes on as many kids live as other sites. ESPN has 1-2 guys making main decisions and they are mostly guesses. Rivals and 247 see many more games, have many more scouts, and share thoughts. They also have some of the best higher ups in the business (particularly 247). Recruiting is what 247 and rivals do, ESPN wants to can it. 247 and rivals spend almost all their funding to get it done right, the four letter doesn't fund much. They show some games, but they don't properly scout the players.
That's the long explanation. To anyone with a brain they know rivals/247 are much better rankings. I do agree ESPN is flashier and good for perception.