I saw it in a theater and watched the DVD today.
No it is nothing like Pearl Harbor. There is some sentimental stuff but it is not tacky. And the film is very historically accurate.
It is in a mixture of English and Czech and German, with English subtitles.
I think there is some recycled aircraft footage from Battle of Britain but most of the footage used was shot for Dark Blue World using aircraft from the Old Flying Machine Company. The credits show several pilots, some of them well known Warbird pilots, as well as mechanics. There are some CGI aircraft images as well. They mix the old footage, new footage, and CGI stuff very nicely.