"Back to Earth" is much much better in the one-hour "Director's Cut" form on DVD than in the broadcast three-parter form. It flows better.
Personally I think Series VII was much better than VIII. It has its problems (e.g. whiny Kryten, hastily-done CGI) but the overall story quality is better. And after shifting to a comedy-drama feel for VII, the shift back to sitcom in VIII feels like a step backwards.