Beware before using Skyliner.
Skyliner has inconsistent service. I have used them multiple times and sometimes they are reliable but in the past two years they were really unreliable. I think it depends on the bus driver. The last time I used them, they failed to pick up the group at the designated place and we almost missed the plane because of it. We had to run with our luggage 12 city blocks in NYC on crowded sidewalks to get the bus. That was a group of 50. They also never apologized even after I wrote and told the owners about the problem.
Inconsiderate of Locals.
Don't use Skyliner Tours. They drop people off at poorly planned locations with narrow sidewalks, cause traffic, and block NYC bus routes - for example Christopher St. Enjoy NYC but not with Skyliner.