I got this on DVD when it came out last year. IMHO it isn't as good as Dark Blue world or the flying scenes in Dunkirk. Its not a remake of Dark Blue World.
Its clearly a lower budget film and most of the action is CGI. Mel Gibson's son Milo plays the role of Johnny Kent who commanded 303 Squadron in the BoB.
Having said that it is a well acted film and tells the story of the 303 Polish Squadron that took part in the BoB. Definitely worth a watch, and well researched but with real financial backing could, and should have been a lot better.