First... no real spoilers below...
It went well, at first the line was very long, however it pretty quickly went down to a short wait.
I was one of the first few groups to get on ride, other than the club 33 people. There's so much to take in, in the lobby and in the collectors room to see. I won't spoil any more.
I went on 6 times, and experienced 4 of the songs/variations. The movement is a lot better than TOT.
If I was focused 100% on going on the ride, I could have easily gone on 10 times.
The monsters inc ride was open, it was a literal walk on when I went on, I might have been the only person on the ride.. The animation studio had a animation class on various marvel characters, and the Hyperion theater had two separate talks with the people who created the new ridemwhich was very informative. There were lots of other stuff to do too and many food choices. I got a very cute Groot sipper cup, and they also gave us a goodie bag when we left which had some rather decent stuff, including a baseball style cap, and a comic book, and more. I also bought a couple things too.
There was a $15 voucher for food, but it was limited, it didn't include alcohol or things like the groot sipper cup.
I left an hour early at a little after midnight.
Bottom line, I enjoyed the new ride tremendously and recommend it highly. The music during the ride makes it so much fun. The ride itself I think is better than tot because of variations and music, but I still like the ambiance of the tot building better.