Like a lot of people I have mixed feelings about Gibson. Undoubtedly he was a brilliant pilot who led one of the most audacious and skilful operations of the war. On the other hand there is a strong body of opinion from those who were around at the time that he was an arrogant, short-arsed little martinet (remind you of any other WW2 RAF heroes btw?). These people often come to the fore in times of war, and we can be admire and be grateful to them, without actually liking them.
That said, there should be no difficulty finding an unpleasant, arrogant sod to play him - the film world is awash with them.
my favourite quote of all time is by Churchill;
"now is a time to try men of force and vision, and not to be confined to those judged thoroughly safe by conventional standards. "
- it worked back then, and probably is a lot to do with what is wrong with much of the way things are done today.