This is marketed as an HD-DVD, and it plays on an HD-DVD player. The resolution, however, is not hi-def. It does have a 16x9 native aspect ratio, but the resolution is no better than any anamorphic transfer to a normal DVD. I don't know why Adam & Eve, which has a decent reputation, would pull a stunt like this, but it was not a good idea.
The plot and a detailed description of the sex has been given in reviews of the DVD. I would add, however, that the sex is boring, formulaic, "couples" sex. The attraction of this title was supposed to be high-definition photography of a beautiful island location; the island is there, but where is the hi-def photography?