His lectures are very good, not too long and on point. He does not deserver to be in the Top 5 and it is a fact.
I had my project with him. Extremely bad, does not reply to emails, does not follow you or your ideas but his PhD students will. I was in good terms with him and he did not even reply when I asked him for reference to apply for a Master. Very good lecturer, very bad supervisor.
He is busy is not an excuse, everybody is in London.