2016-02-10 UTC
# 
jasnell_ actually just saw the question... so semantically yes there's a difference.
{"url": "http://example.org"} is a description of the object itself. It's saying, "this is an object with this url". {"type": "Link", "href": "http://example.org"} is saying, "this is a reference to something at http://example.org". The former is describing the object, the latter is describing a link to the object