Just watched the movie today...I`m retired, so I can!
Some artistic licence for dramatic effect of course, but not a bad film. Quite good, in fact. As SWMBO says, it's intense and is cleverly done. It took me about 30 min to realise what was happening with the plot and the timelines, but once I got my head round it, it was easy to become 'immersed'. (Watch the film and you will see why)
Worth paying a bit extra and viewing it at an IMAX, IMHO. Some lovely Spitfire shots, but ......I doubt that the 'engine off' performance is better than my K6 glider. (One example of the artistic licence)
Not a documentary in any way.. and it failed to reach the level of realism in "Saving private Ryan" but its much better than 633 Sqn.
A curates egg. 6.5/10 Worth a look.