Not Bad, Not Great
I really enjoyed the first film and overall I thought this was alright, but it was just too long and lacked the tension of its predecessor.
I thought the acting was really good, although every time McAvoy stuttered I kept thinking he was going to turn into the Split character. They did an incredible job with matching the adult actors to the kids. I think the biggest problem for me was that every time they went back to the kids, it felt like they were just rehashing the first film, which we already saw, but those scenes lacked any tension because we know they all survive so there are no stakes. As a result the film dragged on. I didn't mind the CGI and actually thought it looked really good. The other major aspect that bothered me was that sometimes the Losers showed no fear towards Pennywise, but it didn't make any difference and then they do it at the end, just like in the first movie, and now it all of a sudden matters and they are able to defeat him. Overall, I thought it was fine, but just not nearly as well done as the first film and much too long.