The new RESTful API produces responses that contain "self", "up", "children" and "id" fields in the JSON response. These names were chosen because they are common within RESTful services. However, if a node contains properties with these names, then the properties will overwrite these built-in fields. This should be changed so that we always generate the built-in fields and overwrite any node properties with the same name.

Yes, this might prevent users from getting some node-specific data, but it is a general JCR best-practice to always use custom namespaces (and prefixes) for properties.