Saw it last night. Visually, it was stunning. Felt like the humor was pretty understated for a Marvel film, and when they went for a joke, it usually landed. And I applaud them for finding a nice balance in trying to do something that is different for the MCU, while having just enough connective tissue to feel connected.
That said, it was just not a "good" movie. Easily my least favorite movie in the MCU, and didn't at all feel like MCU quality. The writing itself seemed poorly done, and while it seemed like they were trying to keep the threat ambiguous to try to keep the audience unsure of what the ultimate threat actually was, the movie never seemed to do enough to make me feel like the writers were confident in defining the threat. It just felt like an incohesive mess.
And another thing this film had a problem with is that it introduced far too many new characters for one film. There wasn't time to develop them, and as a result, I didn't care about any of them. The MCU has done a FAR better job with teams of heroes in past films. All of the Avengers-centric films benefitted from individual characters having solo films or appearing in other films so that when you got to the team-up films, you didn't have an entire team that was entirely new. The notable exception is Guardians of the Galaxy, where they dumped a whole team of previously-unknown characters on us all in one film. But a few key differences made it work: (1) There were only 5 guardians, rather than 9 eternals. Even 5 is stretching it and often could be too much. 9 just compounds that problem. (2) Gunn just did a fantastic job writing the characters to give them development. Draxx and Groot were a bit understated and one-note, but that was fine. We got enough to understand who they were and what their motivations were, but they were designed to be more "support" members of the team, and it worked. But overall, the characters were written incredibly well. (3) The plot itself was well written, and served the characters well. It didn't try to do too much, but the conflict was defined and understandable, and the stakes were such that you cared about the outcome. In short, Gunn didn't try to do too much, and did what he did VERY well. In contrast, Chloe Zhao and her team tried to do far too much, and overall executed it very poorly.
There are other things I disliked about the film that probably aren't worth getting into and debating. But overall, this this film was a fail and confirms where I feared the MCU is heading. Marvel gave us an unprecedented three phases of pretty spectacular storytelling. But they are no longer "must-see" going forward. And probably some storylines I will avoid.
Overall rating: Probably a 2/10. No interest in seeing it again or acknowledging it as part of the MCU. I consider it to be a serious misstep by Marvel on so many levels. Highly disappointing, even going in with pretty low expectations.