Well, kinda hard to answer sorta. I use the API, as far as API KEYS, which allow me to use all kinds of third party solutions. Where as they are doing all the programming, essentially, to the API, and I am just providing the key. Now the playground, has its advantages as well, especially if you are going to use the API in development. Are you contemplating it? No matter, I'd suggest everyone sign up for access, even if you never use it.