Is German music 'heavy'? or 'superior'?

An interesting discussion about the 'heaviness' of German music and its performance tradition, as provoked by British composer Thomas Adès in an interview:

http://slippedisc.com/2015/10/thomas-ades-are-they-serious-some-of-those-old-german-conductors-just-sound-absurd/

Is Austro/German classical music - Bach, Mozart, Haydn, Beethoven etc. up till and including Mahler and Strauss - indeed 'heavy'? And its performance tradition the best way of presenting it? But what is its performance tradition?

Thinking of modern performances by, for instance, Harnoncourt, Sir J.E. Gardiner, Salonen, Van Zweden, this repertoire sparks fire at the cutting edges and is contemporary for ever. But nationalistic chauvinism is as distorting as criticizing it for teutonism.