Just saw it, 70mm non OMNIMAX. I was impressed. A couple clangers, the stuka getting shot by the spit at the end, the little boats all showing up tears in the eyes of Branaugh, those two did wreck my suspension of disbelief.
Otherwise I was very impressed, the handling of the non linear timeline was excellent, if you liked it even a little I recommend you watch Memento, I think it was his first movie.
The music score and sound I thought was really good, I understood about 10% of the dialog but the ticking and the dread of the score were quite effective and had an almost subliminal effect.
I can't imagine how much work it was to make without much CG, shooting on the water like this has got to be a real challenge, and the use of real boats and pushing an ancient French destroyer around with tugs....that all took real skill and hard work.
The flying scenes I thought were hands down the best I have ever seen. I saw an interview where Nolan said that they had a ton more of really good stuff but you can only use a little, they ought to cut together a short for spitfire geeks.
Like somebody else said I kept wanting to yell "shoot" when there was enough lead, (little trouble with the suspension of disbelief there, but I blame AH.)
Overall for you guys that didn't like it or felt Meh I'm genuinely sorry you didn't have the same experience that I did. I felt very emotional during the flying scenes, something about the fusion of flying which is so beautiful and hatred, (I really wanted the people in those 109s and Heinkels to die,) got me choked up.
As for historical inaccuracies in the gear, I didn't know enough for it to matter.