I got the earlier Thor movies and the 1st Avengers movie on dvd on the strength of Thor Ragnarok. They're all quite different in tone to the new movie which is largely comic. Usually I don't find comedy and fantasy mix that well, but I think because of Taika's idiosyncratic vision it does, the comedy isn't just cheap gags. For Kiwi/Australians there are a few local references, the Commodore spaceship and of course the Maori casting and Korg's Maori/Pacific Island voicing. I also think Taika brought out a better character for Thor which always felt a bit flimsy in the other movies, He seems way more lively, human and engaging and fills the role better.
Having said all that I enjoyed watching the other movies, quite entertaining.