Guardians of the Galaxy vol. 2 is the most beautiful MCU film to date, with a colour palette x2 bigger than the predecessor (Guardians of the Galaxy 1), which was before the most colourful MCU film.
Films like Civil War and Avengers all have the same colour palette, but Guardians is not only special because it's not afraid to take risks with it being all in outer space, it's also very beautiful. Every MCU film except for Guardians 1 and 2 have the same colour filter and that makes them ugly.
Apart from the stunning visuals and the well done CGI, the Guardians are good as always, and introduces new characters very well for an already some-what crowded film.
Drax is much funnier and has more jokes, and the overall film has much more jokes. Mantis is developed enough and a great addition to the team. Yondu has a great character arc and by the end you will love him. Ego is is slightly under-developed, with his motivation a bit confusing. Nebula is great and nebula's interactions with the guardians is great too.
The villains as always in the MCU are pretty flat, and the villains are. The first villain is used as kind of a big joke and comic relief but the second i found a bit silly. Too many movies end with all the heroes fighting a massive bad guy, why can't they just fight a whole group instead of banding together to fight this massive bad guy?
The some of the ravagers get more character development, like Kraglin (played by Sean Gunn) who gets a much larger role than before, again as Yondu's second in command. The plot is also fine, nothing special.
11/10 for MCU fans 10/10 for casual, must see with the whole family.