short answer: I'd put it just below Bumblebee in terms of how watchable and quality it is. Bumblebee still remains kind of the Shit I Want from these movies in terms of emotionality and characters and design silhouette/palette. I think this is a good movie that has unfortunately by no longer being a sidestory or spinoff has attracted the stifling gaze of the series' producers whose particularly inclinations sour a lot of the experience.
Spoilers below the drop
I feel like something that's always been a weakpoint for the Transformers movies is that i lose all sense of disbelief when two human characters talk about the CGI robots? It feels like I'm suddenly watching Cool World or Who Framed Roger Rabbit. You can see something in the actors eyes flicker out when they suddenly have to start talking about Optimus Prime, it's really distracting. I think Bumblebee gets away with this because of just how central Hailey Steinfeld is to having to work on being able to relate to a tennis ball she's talking to. This has a bigger cast and honestly...kinda feels like some cast members get it better than others? Anthony Ramos feels like he connects well with Mirage but Dominique Fishback isn't really given that same emotional anchor as Ramos or Steinfeld so she just sounds real, REAL flat when trying to talk about robots.
Maximals were really fucking good, I was surprised at how much time the Transformers got to be characters this time, which felt like a really good takeaway from Bumblebee. It's another fucking globetrotting macguffin plot where these movies really want to be Indiana Jones? I feel like Lorenzo DeBonaventura really wanted Uncharted over Transformers. You can kinda feel the producers fingers over a lot of this. Prime is still super violent, and is being depicted as a world weary killing machine? That was something i had attributed to Michael Bay but it seems like he might not have been the only one responsible.
You can tell because they got a lot of interesting emotions across the faces of the other robots, Primal looks really sorrowful or sympathetic at times and Mirage gets to run a whole bunch of emotions through but fuck man. Prime feels like he's just dragging the show down at this point.
the Bumblebee editing continues to allow for brightly coloured characters being distinguishable and recognizable from scene to scene. Colour palettes and silhouettes are really well-refined and you can quickly identify everything that's happening.
Two out of THREE major character deaths are undone by the time the credits are over, and they're both the boy robots. C'mon. C'mon we didn't even get to see Airazor's fucking robot mode. That sucks so fucking much dude. Especially since Michelle Yeoh gets the most spoken dialogue out of all the Maximals? Fucking sucks. I have her fucking toy! I KNOW she turns into a robot!!! Bring her ass back too.
Scourge's face reveal made me stop dead for a moment because he looks exactly like Ultron and i'm like...don't you do this to me dogg. I know this shit started as Marvel comics. But it turns out the reveal is he's just kinda ugly under there i guess? Then when Doug Stamper from House of Cards shows up at the end and he's like 'I want to recruit you into a special organization' i was thinking Sector 7, the John Turturro org from the older movies, but i started to get this creeping terror it was for SHIELD. DON'T DO THIS TO ME. But then Anthony Ramos looks at the card and it's....GI Joe. GI JOE WAS ORIGINALLY DESIGNED FOR MARVEL AS A SHIELD RELAUNCH. NO! FUCK! NO!