I have stayed at the Marquis, East Side and WTC Marriott and, yes, the lounge at the Marquis is the best. But I loathe the rest of the hotel. It's filled with slack-jawed, tour bus-riding, camera-toting, shorts and t-shirt-clad tourists from the midwest. The neighborhood is lousy and the view from my (large)room is usually looking directly into an office building across the street. The East Side at least is within walking distance of a real New York neighborhood with real restaurants and shopping. Relying on the concierge lounge is fine in Indianapolis or Oklahoma City, but c'mon, this is New York! Leave the hotel and get out there and explore one of the world's great cities. Btw, I have solved the dilema about in which Marriott to stay, I am now in a wonderful 2-year relationship with a New Yorker and stay at his place whenever I'm in town :-)
Paul