Enters Midtown luxury hotel wars with a bang. Dramatic lobby staircase leads to 210 conservatively styled but cosmopolitan guest rooms for the expense account set. 25th floor Spa Nalai for when day’s meetings don’t go as planned. Don’t come looking for scene like nearby rival Baccarat Hotel. Rather, Back Room at One57 does low key luxe for biz clientele, and Living Room is for sophisticated, grown up cocktailing. Posh.