I don't feel the acting plays too much of a central role in a movie like this, as it's based on actual people rather than fictional characters. To overplay them, makes them unrealistic and TV interviews in the 1960s were not incisive enough to allow understatement of the part.
The book paces the film nicely with a straight conversion to screenplay (more or less). The cast are good, less well known at the time of course.
It's the quality of the finish on this movie, the detail which stands out. I watched it two nights ago and was convinced by the scale, flying sequences, rocket flights, space scenes and authenticity of the whole package. Something I resolutely cannot say about many films which are nearly twenty years old.
Apollo 13 which it can't avoid comparison with, looks a hollow movie in comparison. Moments of 'depth' are preceded by meaningful pauses and lots of shouting to signify anger. Again the screenplay could have been adapted with relative ease from Andrew Chaiken's book on the Apollo missions; all the same details are present.
The Right Stuff is a fine movie that deserves its high place for several reasons. Firstly it's long, but not boring (a considerable achievement), secondly the characters come "warts'n'all"- like the irritable Lyndon B. Johnson and 'unlucky' Gus Grisshom - with no resorting to sentimentalism for 'yesterday's heroes'. Thirdly the film is shot with a deft hand. If you look 'through' the movie and watch the story unfold (which is the intention - after all), you'll probably miss how much fore-thought has gone into splicing the scenes together. Some of the shots are tremendously difficult to achieve (particularly the flying scenes) and as well as being densely varied, they give the movie a 'non-cheap' moniker. Kaufman has suffered and slaved for his art and the movie's position in the top 250 is his deserved recompense.