Great if you enjoy the Alien/Prometheus overall story, but not as scary if you're looking for the old "feel".

Rating: 9/10 (5 July 2017)

I think your expectations for this movie have 110% to do with how you'll receive it.
Based on reading a few extremely negative reviews, I was expecting a mediocre film, with poor acting, a horrible story line, etc. - and ended up quite liking this film.
My two sentence review: Alien Covenant doesn't have the horror, and tension building elements of the original Alien(s) (closer to Prometheus' overall tension in that regard), although it certainly creates an eerie and mysterious environment. However, the story is gripping, especially if you enjoy the mysteries that came along with Prometheus and Alien in general, and I would not suggest skipping this one unless you thoroughly hated everything about Prometheus.
I saw no flaw with the acting, and to list every little thing I would personally change (or deleted scene I'd add), is pointless, and arrogant/ultimately insulting to Scott and everyone who made the movie.
If you enjoyed Prometheus - watch it. If you don't care about Engineers, Prometheus, where Aliens come from, and any such questions - if you only want a horror movie like the original Alien, then perhaps skip this (and re-watch the original Alien(s)).
To be honest, for anyone who's seen the first two Aliens enough to remember a few meme- ish quotes - I'm not sure what variation or new movie/take ANYONE could come up with, that would feel "new". Any variation would simply feel like a "The Forc.." I mean "The Aliens Awaken" rehash of the original, which is why by now I'm probably more invested in the overall narrative of Scott's universe, more so than expecting the "most horrifying experience".
Hope this helps.