yeah the quality of the picture is the most important thing about a movie
I don't think anyone is saying that, but there's a stark difference in picture quality between the TMP DE on DVD and the theatrical cut of the film on Blu-ray. The latter is significantly more detailed and solid-looking. The audio is clearer and punchier on the latter, too. That said, the DE probably has a more faithful colour tone, despite the much duller- and muddier-looking image. On the Blu-ray, everything is way too blue-looking. Not to mention persistent noise-reduction, plus some very obvious black crush in the space shots, etc.
And yes, from an editing standpoint, the DE is the superior version, reincorporating several key character moments that were unfortunately tossed aside in 1979, and offering a more complete audio-visual experience (some odd/grating decisions aside). I think they could have left the V'Ger flyover material intact. But, basically, to me, it is the superior presentation -- even though, on a technical level, it is sadly lacking at present, stuck at DVD resolution and desperately deserving of a 4K remaster. Once the DE gets a remaster into the HD realm, then we can better compare the two. Right now, the theatrical cut has an unfair advantage, and it's a not-insignificant one.
On another note, I think I take back some of my negativity from
an earlier post. I was re-watching the wormhole sequence the last week or so. I find the DE version much more palatable and far more "complete". I had forgotten how much I actually prefer the latter. For one thing, despite my earlier complaint about the altered Red Alert klaxon, I actually like how the new one plays in the background and drags out in a doppler-effect, dream-like manner as the Enterprise "burrows" farther into the wormhole. And the added effect of the Enterprise blasting free of the wormhole makes the sequence feel much slicker and satisfying. It's just a punctuation mark, but it makes quite a difference. And yes, I know, the original was rushed and they might have done an even better job with more time, bla bla... Overall, the DE justifies itself, I think. But damn, we need an upgraded, UHD version....