While I'm not the biggest fan of the series, I must give credit where due. The people behind the franchise have been pretty consistently besting themselves with each new entry in the series. That's not a given (just look at all those 80s horror franchises), especially when you're already 8 films in.
I will say that "besting" is pretty much limited to making the action bigger, crazier and more explosive. If you want serious character development, a solid plot or engrossing drama you better look elsewhere. If on the other hand you're content with some of the best action scenes ever put on screen, F8 has you covered.
The cast does a decent job, though mostly because their characters are tailored to their own personas. The introduction is a bit long and Theron is a disappointing villain, but once the car action begins that's all quickly forgotten. The film doesn't really slow down after that and the finale is one of the best in the series so far. Good fun.