I'm sure that Donald O'Connor gave Buster Keaton the performance of his life as he would like to be remembered. It certainly wasn't anything close to the life of the real Keaton.
In his prime Keaton, Lloyd, Laurel, and Chaplin contended for being the greatest of silent screen comedians with most conceding Chaplin was best. The others are still remembered for their wonderful routines and for the fact that they survived and made the transition to sound. So did the real Buster Keaton, but not as a star.
The best part of the film is Donald O'Connor recreating some of the classic routines that Keaton did from the silent screen. No doubt Buster worked with O'Connor because he sure got them down quite well.
Ann Blyth and Rhonda Fleming played the women in Keaton's life composites of women he was actually involved with in real life. Peter Lorre has an interesting part as well as a director who Keaton runs roughshod over in his star days, but who Lorre rather subtly gets back at when the movies transition to sound.
In real life it wasn't as simple for Keaton as talking or not talking. When later on he did do the bit parts in films that he scorns on the screen when producer Larry Keating offers him a role, Keaton did have a voice that matched his stoic stone face.
One thing I disagree with. In his case it was right for him never to crack a smile, very much like George Burns. But people like Red Skelton were always laughing at their own material and the audience didn't seem to mind. Different attitudes get different latitudes.
The Buster Keaton Story is not a great film, but O'Connor does well in the role and I'm sure Buster liked it.
