Full spoilers ahead to save you the headache.

Rating: 3/10 (10 September 2019)

The three stars are for Bill, the creature design and the CGI budget.
So much time is wasted. 20 minutes of nothing but swearing or wooden acting followed by a one or two minute CGI scene that ends in a jumpscare. It's a rinse and repeat formula for the entire movie. The preformances from most of the "adult" version actors feels very phoned in. Bill Hader was a terrible choice as was Jessica and the guy that played adult Ben. Wooden and stiff throughout.
Thankfully Bill Skarsgård's odd yet terrfying portrayal of Pennywise carried the entire movie, the downside is they've piled so much CGI on top of him it really takes away from the dominant portrayal he had in the first film.

Whoever designed the forms Pennwise takes (aside from the ho-hum zombies) needs a serious raise because this film truly has some really effective monsters in comparison to the first. It's just an absolute shame all the "scary" parts are overloaded with CGI, while I understand practical effects can't be used everywhere something more grounded in reality is much more terrifying than the 90,000th movie with 90% computer generated things. Considering all the actors were more than likely forced to act vs a green screen rather than Bill's Pennywise it may explain why the majority of the actors seem to be bored and just reading lines.
I also wouldn't consider this a horror movie after sitting through the poorly paced nearly three hours. Long movies don't bother me but them being long AND boring for vast amounts of screen time do. So much comedy has been forced into every other horror scene it's like someone watched a Marvel movie right after watching IT and said "yeah lets do more of that". It was a bad call and the movie really suffers from it. There are a few really great scenes such as the old woman's house, and the two with the young children in the first half, funny how with the kids both scenes are mostly actually Bill as Pennywise rather than 90% CGI with Bill's face stuck on it. The same cannot be said for the actual jumpscares.

I know in the original tv miniseries the giant clay-mation spider at the end got a lot of flack, well this version suffers the same fate except instead of clay-mation it's some hastily done you guessed it CGI. The ending is really so farcical that the threater errupted in laughter at Pennywise being "bullied to death". I am 100% ALL for an anti-bullying message but this is supposed to be a horror movie for adults not Naruto where love and friendship wins the day. You will be rolling your eyes during the last act and the superly hard forced "sad moment" feels very cheap because of it.
Very disappointing after having the expectations after the first movie set so high, save your money and stream it.
PS: Stan Lee is the epitomy of the creator making a cameo appearance in movies, it seems now that the man has passed on others want to get in on it. Next time Steve, leave the acting to the actors and just say no. Such an unnessesary cameo.