The theatrical version was excellent. It had a strong, if simple story (sometimes it seems as if only the simple stories are strong, at least in movies,) combined with an amazing visual style that was sensibly imitated thereafter. It was thematically coherent, about what it means to be human. The main drawbacks were the narration and the final scene.
The problem with the drawbacks were not Harrison Ford's flat affect. Aside from being something of a noir tradition, Deckard is a burnout. Without the narration, I've noticed Ford's Deckard seeming a little too innocent, to surprised by stuff to be quite as believable. The problem with the narration is how repetitive and uninformative they are. The stone cold killer Deckard not quite getting Batty's decision to let him live is particularly useless but hamfisted. The only time Ford's narration serves a genuinely useful purpose is in the final scene, when it underlines the commonality of Rachel's uncertain life span.
And that is important because it completely recasts the sappiness of the hero going off into the dawn final scene. It is always amazing to me how often people who claim to love ambiguity generally refuse to see genuine ambiguity. The voiceover says no one knew how long she had. Just because there's finally bright light doesn't mean she's going to live forever (which would be another kind of unhappy ending for Deckard, anyhow.) She could stop the next day. The narration puts back in the ambiguity of her fate.
Given that Gaff was shown folding and dropping his origami figures before, the unicorn means Gaff was there (the narration explaining this is another good example of how most of it is entirely unnecessary.)
The idea the unicorn dream is needed or desirable is nuts. Which means the notion that a bad movie was fixed up into something good is equally nuts. The notion that Deckard is a replicant doesn't undercut the question of what is human is dubious enough. If a replicant is an assassin whose life is spared by another replicant and said replicant falls in "love" with another replicant, it's all kind of trite, just members of the same club hanging together. A human falling in love with a replicant, a replicant sparing a human who had no mercy himself, these raise the thematic stakes.
But there is a value judgment implicit there. Which is, if the replicants are in fact human and the world of the Blade Runner is contaminated with a Big Lie, then the use and retirement of replicants is in fact slavery and murder. When Roy Batty kills his creator Tyrell, if he's human, he's enacting a response we should feel toward a creator who inflicts death upon us after too, too short a life. For people who accept God's decree, and (or) who feel some "people" are not quite the same as the rest of us, or are inevitably enemies, and should in fact be treated differently, the director's version is more comfortable.
But the notion that the director's interpretation is "valid," strikes me as abandoning all common sense. The plot of the movie is completely senseless if Deckard is a replicant. Unless you think any series of vaguely related scenes serves as a movie, this makes the director's version invalid.