Mid-50's here and really didn't like Lynch's version that much, but was quite underwhelmed with Part 1.
That said, I think you nailed the two movies in two sentences.
Of Lynch's version I often quip that it was both good and original - however the parts that were original were not good, and the parts that were good were not original. In short - I did not like the divergences from the source material that much. It did have a soul though.
Part 1 seemed to miss or give short-shrift to beats in the book that always stood out to me. Instead of really conveying the absolutely oppressive lack of moisture on the planet, there was what felt like an interminably long monologue about the palm trees. Mentats with inner eye-lids? Leaned into the mystical side too much for my taste. Yueh's betrayal seemed like a footnote. The end of the movie from when Paul and Jessica met the Freman felt rushed. More time spent on why Jamis was so pissed off, and reflecting on the fact that this was the first man Paul killed, and less on weird alternative time-line future WTF visions would have been time better spent. Sterile and lifeless.
Add to that, did anyone else not know that it was a part one and not a complete movie when they walked in? Definitely seemed like something that they went to lengths to conceal.
That said, I'll watch it again before watching part two, and then try and form an opinion of the complete movie and not just the first half.