The completion-in whatever form-of a major masterpiece like the Bruckner 9th or the Mahler 10th, or, in the case of Dutton, Moeran's 2nd or Richard Arnell's 7th (both of which are actually realisations rather than "completions") I can and do cherish enormously. These may not be as the composer intended but they are faithful attempts to do so.
My feelings exactly. I would also add Payne's realization of Elgar's 3rd. Not a masterpiece on the level of Bruckner 9 or Mahler 10, but a work I've come to like very much, nonetheless.