As a Diamond member, I'm all in favour of moving from hotel to hotel when travelling light and picking up another 1,000 points amenity bonus for each stay.
New first-time hotels is also good for the Milestones program, although there's no guarantee of being targeted for each milestone.
http://www.flyertalk.com/forum/hyatt...getted-25.html
I echo the comments that for Broadway/Midtown, it's no big deal to take the train from New Jersey as opposed to staying downtown.