I also find myself in a bit of a quandary regarding an upcoming Saturday night stay during a quick leisure trip. I used my last confirmed Diamond suite upgrade from 2011 to reserve a suite at the Andaz 5th, but overall prices have gone down and I see there is now availability at the Andaz Wall St for about $100 less than my existing reservation. If I switch over to the Andaz Wall St, I waste my upgrade and probably wouldn't spend a new confirmed suite upgrade just for a one night stay (since I'm not just looking to burn an expiring upgrade anymore).
I'll be flying in on a red-eye so I'll get in early Saturday morning and was hoping for early check-in before I hit the town. Would that be more likely at Wall St? Is the cost savings also worth the extra taxi expense if I want to spend most of my time at the Met or other places around Central Park?