X isn't the remix version, but neither is it the original release. The original was on 8 discs, with stereo sound in both languages. The remix was on 5 discs with 5.1 sound in both languages.
The UK release is from a R4 Madman master, with 5.1 English, 2.0 Japanese, and as for the video quality, it's pretty nice (although I don't know if has been remastered), I think it's going to be a six disc release (V 1 has 5 eps, V 2 has 4 and for a 25 ep series that would make sense)
The weird think is that Madman haven't released X in Australia, there was a R4 release a while back from one of the little companies, but that was across 3 discs!