The plot is remarkable, and is something you can make a film of. The concept is there, but the execution is lacking. I felt there was a lot of untapped potential. For starters, DTT could have used more wit and humor. Sure, there are comical stuff but don't expect anything extraordinarily funny.
Sex is dealt with a certain frankness that makes it seem very natural and even humorous.
Sexual scenes are tastefully done and not out of place in the flow of the story. No La Blue Girl type of stuff here. My major qualm about DTT is the art. In some panels, things look okay. But in others, the characters' faces look anywhere from slightly or severely assymetrical to downright deformed.