I live in DC, so don't typically stay in hotels there, but I applaud your decision to avoid the Holiday Inn in SW. I've been to numerous meetings at that hotel and it's dingy and has a government office in the middle of the lobby. (Literally. Weirdest set up I've ever seen--the entrance to FEMA is in the hallway between the main lobby and the meetings rooms. Our meeting participants from out of town frequently need to be reassured that they don't need to show ID to get to the bathrooms located further down the hall.)

The Mandarin Oriental in SW DC has an excellent reputation and is walking distance from your hotel. Otherwise I would try any of the name-brand downtown hotels (Hyatt, W, Hilton, etc) and grab a cab to your meeting destination. If you have down time outside of your meetings, you will have a greater choice of restaurants and other amenities if you stay in downtown DC north of the Mall.