Ritz is definitely nicer, but the W, Hyatt Regency, Westin downtown, and the Le Meridien Stoneleigh are all perfectly fine hotels. For a special occasion, the Ritz may be worth the price increase, but for a regular trip, I don't think the Ritz is worth the up charge unless you plan on spending a decent amount of time at the hotel.

If you don't have to stick with SPG/MR, you might also look at the Joule; it was always my favorite hotel in town until it left SPG years ago.