Very good overall. Excellent location in Philly - close to everything (esp. museums) but excellent access to 676 for getting in/out of the City. Take advantage of their complimentary car service - an S-Series Mercedes beats a cab any day.
Rooms were very comfortable, we had a good view of the fountain. My two main complaints: 1) our room was loud - not from the hallway or outside traffic, but from the adjoining room, as if there were no sound-proofing. 2) the housekeeping missed a few things (like leaving a used wine glass hanging out for a couple days, not giving us hand towels).
Breakfast and valet parking included in our rate - was a great value overall.