Reading back, this is more a list of what I didn't like. But maybe that's easier to write up. Sorry.
Overall, I enjoyed the game, I really did. It was, as I said before, pretty much the style of action RPG I expected from BGS, but for now, my need of playing it is satisfied. I think I did all the major content (the main quest, all three faction questlines, the companion quest, the Mantis quest, and a crapload of little side missions, and I unlocked all powers). I did not get into outpost building a lot, because I don't enjoy base building, and I didn't get into ship building beyond upgrading. For the most part, I flew the Razorleaf, which I upgraded over time with better weapons, engines, jump drives an reactor, and I rebuild the Frontier to reflect that build for a possible NG+, so technically that's my only scratch build. While the ship building interface is nice and it's fun to tinker around, I just don't have the creativity and patience for it. I also didn't really do planet exploration, because... it's boring.
While doing that playthrough, I felt the constant itch to keep playing; at least as long as I had "major" things to do apart from the main quest. After finishing the other major content, finishing the main quest became a bit of a drag, and the urge to keep playing was replaced by the urge to finish it; a sign that I've had enough. Overall the main quest was just meh with too many fetch quests; the concept of creating a NG+ loop is a nice idea though. Typical Bethesda, I would say, a "meh" main story that makes you visit the places to get side content. I really enjoyed the faction quests, I thought they were pretty good fun.
I also found the characters just "meh". None of them really made me care about or hate them, and the companions were pretty bland - pretty much all characters were, now that I think about it. The companions also were annoying, because they kept either running off and starting fights when I tried to sneak through a building complex, or kept running in front of my gun when I tried to scope enemies. Also, I didn't really like any of them, and they were no fun. I remember back in Fallout 4, I really, really enjoyed some of the companions, and they made the game more fun (my personal favorite was the potty mouth of Cait, and traveling with Nick and Codsworth was always fun). In SF, I pretty much kept them around, because affinity and companion quest. And I left them behind as soon as I was through with that. That's generally a bad sign, I think.
Also, while the world building in general was great (as always, BGS are very good at that), there was too much repetition. During all the missions, I raided some building assets multiple times with practically zero variety. The few cities I found too... convoluted? I don't know. Seems like they tried to cram as much into the cities as possible. Same for some locations, some of them were just too large and complicated just for the sake of being big in scope. Again, compared to FO4, I missed something similar to the wastes of Boston, where you could actually explore and run into all kinds of different places. That's a big miss in my opinion. I was okay with the ship travel system (a.k.a. loading screens), but usually I try to play these kind of games without fast traveling; Starfield was pretty much built around it. Having said that, I got annoyed pretty quickly by all the animations - landing, taking off, getting out of the pilot seat, opening airlocks... that was annoying.
I did not at all care for the "powers" stuff of the main quest. The only ones I ever used were the personal atmosphere and the one showing me where people are. I don't really care for "magic", and I thought the integration of Clairvoyance into the scanner was dumb. On the other hand some locations were so confusing to navigate I had to rely on it multiple times. I didn't like that.
While kind of streamlined, I also thought the weapon and armor crafting was a step back from Fallout 4. And in that regard, I really didn't like the "challenge" system. Also, not being able to take off mods from looted weapons was a big oversight in my opinion. It was one of the more fun parts of Fallout 4.
I had three quests I could not complete because of bugs; I cleared them with console commands. Apart from that, the game was pretty bug free for me. A few physics glitches here and there, and one crash, but overall very stable, and good performance.
What else... I don't know. It was a fun game, it really was, but I don't see me sinking another 150 hours into it any time soon. Maybe after a year or so. Maybe not. It was a good, solid game, and I enjoyed it. Great? Eh, not really. Overhyped: Definitely. But it was entertaining while it lasted.