So I just Cars 3 and here's my mini-review of it.
So I would say this is an undeniable leap in quality from Cars 2, generally and objectively speaking.
The racing/action sequences were actually very exciting to watch. The story, while a very prominent one in the sports movie genre, was handled well here and it was interesting to see how it played in this particular franchise. The characters were well realized, they did some excellent choices with McQueen and Ramirez, it surprised me in that regard. I actually think this one is the best structured and paced of the three films, it wasn't slow or fast, it took it's time to ease us into this new adventure and the development was nice and balanced with an appropriate runtime. The animation is obviously fantastic, but that is pretty much a given at this point with anything Pixar.
While it is commendable that Brian Fee tried to breathe new life into the exhausting franchise, the story, (while good) became very predictable. One of the things I like a lot about the first Cars, is that in the end, McQueen doesn't win the race, and his decision and the way the race played out was unpredictable and exciting. The last race here is the opposite of that. Also, with a lot of the story choices, it is obvious that this was directed by a first timer. (He does avoid a lot of amateur decisions though) The movie tried to do some emotional things in the end with some characters and they tried to have a direct parallel between two McQueen and another character, (spoilers) but it just felt so on the nose and amateurish. There could've been many different smarter ways to accomplish the same thing. And the ending was wasted potential, but i don't want to get into specifics here, as I'm trying to keep it spoiler free.
Overall, this is a very good movie, I really enjoyed myself. While it falls far behind Pixar's best work, it is a nice addition to the Cars franchise, even if it is a (very) unnecessary one.