I've been using the WP-API for a custom project where I created Custom Post Types with Advanced Custom Fields and it is really simple to pull all the data that I need. I was able to modify ajax scripts I already had to pull the data and parse it out.

The project I am working on has a google map integration that will pull some of the information from these posts, and the pins themselves will use the data provided from the WP backend. It is really awesome how far the API has come and I look forward to using it more in the future.