Conversation so far:
What was Cary Grant's acting legacy?
Biographers Morecambe and Stirling believe that Cary Grant was the greatest leading man Hollywood had ever known.
What did people who worked with Cary Grant think about Grant?
David Thomson and directors Stanley Donen and Howard Hawks concurred that Grant was the greatest and most important actor in the history of the cinema.

Question: What did Hitchcock say about Grant?
Self-contained rewrite: What did Hitchcock say about Cary Grant?