One of the main drawbacks to the HTTP Accept header approach for both versioning and content negotiation is that it makes it less convenient to test from a brow

One of the main drawbacks to the HTTP Accept header approach for both versioning and content negotiation is that it makes it less convenient to test from a browser when you can't encode those things in the URL. Personally I feel that using the header feels more "right" and lines up with the available mechanisms of HTTP. I think the inconvenience could be easily overcome with browser plugins, for example.