I had the misconception that the order of the Accept types was also driving the negotiation procees. After reading [the Spec](http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.1) again I learned that quality values are the only way to express preferences by the client. So for now ```respondWithMediaType``` ist necessary.

Thx again for the clarifications!