I really got a kick out of Connery in The Longest Day. There were a few little things that made me do a double take in that one (both book and film), the poor guys who put their boots on the wrong feet, the two opposing squads who were so shocked when they passed each other that neither started a fight, bagpipes on the beach, a number of others.
I read Band of Brothers some time after seeing Saving Private Ryan and have not watched SPR since then. Interestingly enough Hanks produced Band of Brothers after SPR. I must say I got into Band of Brothers more than any other WW2 film or series in recent memory.
And while Jermo is correct in stating that the purpose of all movies excepting documentaries is to make money there are some types of people involved in the movie industry who also want to do their best to get the story right, as close as they can. Midway, A Bridge Too Far, The Longest Day, and We Were Soldiers (not WW2 but still a pretty good example) all can fit into this category. A few things always get changed from books or history to the screen sadly.
The films of that era were different. Not just the acting but special effects and the types of things in film in general. John Wayne always seemed to play John Wayne (which is fine with me by the way). There were a lot more films of that era that I don’t mind watching with my kids awake. But I can’t watch Saving Private Ryan or Band of Brothers with the little ones awake.