Explorer Pass worked well for us because it gave us the flexibility we wanted as we used it over a 4-day period. We used the last activity, Top of the Rock, just 1 hour before we were due to leave. Best trip was the Boat trip to Liberty and Ellis Islands - getting almost sunburnt in November! Simon the Guide on the Hop-on-Hop-off was great! Just make sure that you cash-in your voucher and get actual tickets for some of the activities, eg bus and boat tours. I didn't notice any advantage in being able to jump the queues, we still had to queue, but in November this was not too bad. Would I buy a pass again - YES, it helps to plan a little when in NY for only a few days as there is so much to do and see.
It's a great way to see the NYC sights - and great value!
While I enjoyed the activities I chose (Top of the Rock, a Twilight Boat cruise and MOMA) I didn't feel it was great value for money - we had to chose carefully to make sure we 'spent' the cost of the Explorer Pass. Also, I wasn't aware that we avoided any queues - still had to queue for Top of the Rock. So I wouldn't buy a pass again, sorry!