Taxis are a good option and not too expensive. There should be plenty at the terminal.
Why not google new york taxi's & arrange a pick up. Yes the queues can be horrendous, but it's easily arranged over the 'net' .
How fast you get off the ship depends on which cabin and deck you are on. That, unless you are self help, dictates the order of disembarkation. Weather also plays a big part. If it is raining taxis are busy and the journey takes much longer. Having said that, if you are off reasonably early and a taxi is available the journey is good and should cost around $30 including a tip. Thats what we paid to the Helmsley on Central Park last year. Enjoy your cruise and good luck with the transfer.