Personally I did not like him either, after all he agreed to be a politician. But as an outspoken expert for the EU treaties and dictate of Lisbon, his criticism of these weighed heavier than the occasional chatter by ordinary Joes and fanboys. Much of what he criticised in deformations of EU development , shared by for example Giscard d'Estaing, and some others.
For the non-Germans: Herzog was German state president and before that president of the Bundesverfassungsgericht at Karlsruhe.