This worked extremely well. We bought a 5 attraction pass. In the event we only used it for 4 visits but still saved a considerable amount on entry fees as well as being able to jump queues as some locations have voucher only entry points. Well worth it
Very easy to use, only disappointment is that the national 9/11 museum is not included, didn't realise this until after we had purchased it. Apart from that we had no problem with using it and saved a lot of money by not buying individual entry tickets.
Make sure you read the fine print for each attraction. For example the Statute of Liberty and Ellis Island is for the ferry ride to it and not for the attraction itself. Overall it does save money.