Also saw It tonight, agree with others that it's entertaining and creepy--Pennywise is just DAMN creepy, much better imo than Tim Curry's take. Think of Jack Nicholson's Joker compared to Heath Ledger's Joker lol...the movie was also funnier than I was expecting, and all the kids were really good, especially the young girl who played Beverly. I agree with @drowland in his spoiler text about one of the characters, hadn't realized why I was thinking that way until I read it, though.
The movie may have the Mother Of All Jump Scares in it, too lol...
Also, and this is no real spoiler, the movie is supposed to take place in 1988, but doesn't feel like it. Felt more like it was taking place in the late 60s for a large part of the movie. On the other end, I thought i saw a high school student talking on a cell phone in one scene lol...outside of one very funny running joke that speaks to the late 80s, I didn't get that feeling of a particular time in the past.