"Piece of Cake" seemed a pretty fair book to me - certainly accurate from what I've read elsewhere in terms of the RAF using incorrect tactics, formations etc etc early in the war. Even Douglas Bader said so! Therefore if people don't like to face that fact, tough.
I was a bit taken aback by the vehemence with which some people condemned the TV version. They can't get it all right, poor souls, and we did get to see some lovely flying bits.
It's the documentaries on TV that upset me. The number of times that incorrect bits of film get trotted out - Spit V's & Fw 190's appear in the Battle of Britain with monotonous regularity! Now the people who make those programmes really ought to know better, or hire someone who does.