So to be clear... I haven't stayed here. I'm reviewing this solely on the "should I add this to my Vegas itinerary of things to see/do".
I think New York New York is fun for kids and adults - but not in the kitschy way that Circus Circus is. The roller coaster is a small one, but it provides enough of a minor thrill to be worth it - In fact I like it so much one night we bought the unlimited tickets and rode it for an hour or so. Alcohol might have been involved.
Besides the arcade area and the roller coaster, there are plenty of cool things to see inside. The place does hit the highlights of touristy NYC.
I would definitely add a stroll through New York New York to your itinerary - checking out the roller coaster, the Hershey Store and feeling a tiny bit like you're walking around a super clean Times Square - Disney version.