I don't have too much knowledge about this specific hotel, but i do know that it generally gets good reviews. (and that it's about a 10-15 minute walk from my often recommended Ess-A-Bagel, which arguably has one of the best bagels in the city!) However, with most sites not yet returning rates for these dates, it's difficult to stay if this is a deal worth locking in at the moment or not. (although this dates range does include New Years Eve which is historically one of the busiest nites of the year in NYC)
One advantage of the Affinia Dumont is that the rate is refundable so you could lock in this rate while you wait for better offers in the months to come... should other offers not come to fruition, you can stick with the current deal.
If you do decide to stick with The Renwick please use this previous link to make your booking.
Let us know what you decide or how we can be of further help.