We went to the one in NYC. It’s probably a great experience on a weekday, but we were there on a weekend, and it was terribly crowded. We purchased tickets online, but still had to wait outside in a ridiculously long line for 30 minutes before they let us in. We were fortunate to have good weather.
There are 5 or 6 stations throughout where they serve you a free scoop of ice cream. The ice cream and flavors are very good, but there is only one person at each station, so each one had a line about 12-15 people deep. Basically, you get to a new room and just get in a line. And because it was so crowded, it was pretty stuffy and hot in some of the smaller rooms and the tunnel. Not a great experience.
There are some really fun elements- the spiral slide, the sprinkle pit, and a small indoor playground. That, plus the free ice cream, make this a good place to visit if you have kids. They will love it, but they will likely also complain throughout about all the waiting.