I'd say the sub is pretty accurate to the Japanese dialogue (although they do translate the "Children" designations to "Child").
The dub translation/dialogue alteration is somewhat liberal (as per most ADV dubs), and has quite a few bad casting decisions, as well as numerous name mis-pronouncing errors.
Death & Rebirth is a two part film compilation.
Death is a summary of the TV series, with some new animation and footage from the Japanese Special Editions of some episodes.
Rebirth is a preview of
End of Eva, basically featuring the first 15 minutes of EoE (before the Eva 02 vs Eva 05s battle). The US version is exactly the first 15 minutes of EoE, while the Japanese version was slightly different, but not enough to bitch over.
The End of Evangelion is the official ending of the saga, and replaces the last two episodes of the TV sereis. It basically follows the TV series ending, but concludes in a totally opposite direction.
Manga Entertainment (Boo!!) released the two films, while ADV released the TV series. Manga's behavior concerning the DVD release of EoE was horrible (typical of their responce to defective products), and they officially denied that there was a problem with the disks, despite an inside source revealing that Manga was aware that over 7% of the first pressing batch (about 5000 out of 72,000) were defective (the disks would lock up at the layer switch). Amoung current problems with most of the remaining DVDs is that the language screen doesn't work (you have to use your remote to return to it after the film starts to switch audio/subtitles). The title is also non-anamorphic - presented in letterboxed full-frame.