Long time reader of the site - it's brilliant and I'm a huge fan of the franchise generally.
I also write as a fan of Prometheus.
After watching Covenant, I feel that Scott may have felt frustrated after Prometheus, not because the franchise had 'cooked' the Alien, but because his audience no longer wanted to be challenged by film. The audience whinges about unanswered questions, having no patience to wait for a longer story to unfold must have affected his motivation for returning to the franchise.
The result is this film, where Scott ticks off every cliche in the (now literally created) book.
It all starts well, with a set-up that introduces a great cast and draws you into its world - I was a huge fan of that.
However, once a foot is placed on the planet, the pace is relentless, cramming in an army of ideas into the rest of the movie. Potentially stunning images flash by with no time to linger - for example, David's workshop.
My major gripes lie with the Aliens themselves though. A scene where David calms and controls a Neomorph strips away nearly all of the mystery. The chestburster sequence is rushed, and ridiculous - to film the Alien raising its arms to copy David, coupled with the music in that scene...surely it's visual sarcasm from Scott? Surely it's him flicking the V's at those who simply wanted more Aliens with none of the challenge or risk that used to come with it.
I'm not one of those fans who wants ideas to blend perfectly with the past - I say take liberties, change things, Cameron did. The idea of David creating the Alien is a good one. It's the execution of those ideas that make the film feel unsatisfying.
Overall, I wanted to love it. I really wanted to. But the breakneck pace, coupled with how Scott develops the Alien are film-breakers for me. Behind closed doors, my belief is that Scott didn't, and still doesn't want to use the Alien. A (metaphorical) gun was held against his head in these troubled franchised cinema times and he had to use them. At times, you can feel Scott's bold ideas rubbing against those that feel studio/lunchbox/t-shirt selling ones.
Some will praise it just because it's an Alien film. When I left the cinema, I was disappointed. It's a sell-out - for all the wrong reasons.