I think Parse is an awesome platform and was really well documented. I used it for building my app, and will probably end up migrating to my own parse server and then decide where to go from there.
Parse really made it easy to get an app running. Especially a couple of years ago, when api's were complicated.
I'm going to miss the push notifications, I just implemented them and they work really well. Hopefully an open source solution will get released so we can continue using them.
This is a game changer. Love this idea, and also would love to see other big social networks using the same technology to make our mail more interactive.