FIRST REVIEWS ARE IN!
https://editorial.rottentomatoes.com/article/it-chapter-two-first-reactions-epic-brutal-and-scary-af-but-does-it-stick-the-landing/
These are just snippets, but it gives a clear impression of how the movie will be received by critics, but it's how audiences will receive it that will make sure it has legs or not.
I'm a bit disappointed by the fact that some of them don't consider it as good as the original, but then the original was a special event and was always going to be hard to follow.