Good way to see a little or a lot. We chose 3 attractions - The Rock, a museum and the Brooklyn walking tour. If doing the walking tour I would do a week day rather than weekend when bridge is exceptionally busy with walkers and bikes.
We were very happy with the explorer pass. We had the pass for 3 Attractions MoMa, Hop On Hop Off Downtown and Top of the Rock. The pick up was easy and the best thing was the fast entry - especially in the Moma we could avoid huge lines in front of the ticket desk!
It was not really much cheaper than buying tickets directly in NY. We paid EUR 70 for the Explorer Pass. Top of the Rock and Moma is ca. 25.00 EUR - and Bus depends on the vendor...
You see the sign for this pass on the attractions everywhere, I just wish you could collect it from more places, but it was easy to pick up once we found somewhere close to the hotel and was ready to use straight away.
It was well worth it, while we didn't have to skip the queues, the facility there and it worked out good value for money. Would recommend for this only needing 3 to 5 attractions.