I've had the pleasure of mixing it with Dennis at 2 World Championships and several other helicopter championships.
Not only is he a legend, he's a damn fine bloke, who has an awesome track record of safe - and hugely entertaining flying.
I'm nearly half way to his record of "not crashing in 56 years of flying". When I achieve that, I'll feel qualified to comment on issues such as flight envelopes, upside down manoevres and the like.
Until then, I'll take every opportunity to learn first hand from people like Dennis who have dedicated their lives to helping people learn to fly better by passing their immeasurable skills on to others.
See you in Eisenach, Dennis!
Big Ls.