|Rahxephon-Volume 1: Threshold||=|
The Region 1 version of this disc was released earlier this year. As far as I can ascertain, the two versions have the same features: they have the same episodes, same extras, and the R1 even has the same arrangement of soundtracks, with the Japanese being stereo, and the English 5.1.
You can probably be happy with either the R1 or the R4.
The R4 is available in two versions. The disc is the same in both. The only differences are that the more expensive version has the collector's box and a T-shirt. The collector's box is sized to fit all the volumes when they are released — the artwork on the box is attractive, and the box itself is well-made. If you like to keep all the volumes of the set together, and you expect to get all the volumes of this series, then the box is worth having. The T-shirt has a reasonable picture of the RahXephon on the front, and nothing on the back (I liked the Noir T-shirt better).