I enjoyed this but not as much as the first one (which was an unexpected pleasure for me).
I agree with the comments re CGI, sometimes it went too far and beyond the 'suspend disbelief' stage so you were just sitting there smirking at it.
Was this intentional? It didn't seem like it - but then there was a heavy comedy element throughout, really helped along by Bill Hader who I thought was great in it.
I really hated the scene right at the start, that establishes the return of violence and bad things to Derry. I think it was just about justified, but it was a bit close to gratuitous too - I know it's in the book as well (which I haven't read).
The length didn't bother me, I was absorbed throughout.
I think it was made with real passion for the source material as well, that came across.
I do think it was a little bit of a missed opportunity to do more effective scares. I love horror when it gets under your skin by hinting at wider sometimes not openly acknowledged fears and scares, eg the racism/abuse/guilt stuff that's under the surface in Derry. This film went a bit too far over to carnivalesque spectacle.