Strange errors that describe nothing and are untraceable, strange things like JSON not being accepted, I can’t find docs that reflect latest versions or comprehensive docs at all, only scattered stack overflow topics or github issues. Things keep changing. It doesn’t strike me as usable and I’m thinking of trying out the alternatives mentioned here:
I would suggest ebryn/ember-model as an alternative to Ember Data. I find it to be easier to get going with and much more flexible. The community supporting it is also very responsive in IRC and online.
Also be sure to update your Ember Inspector extension for Chrome. They just added a Promises tab that will help trace those kinds of issues. It saved me a lot of time and stopped me from going down rabbit holes.