I stayed in the Renaissance Washington, DC Hotel for one night after spending the previous week in a different hotel for a convention. The staff was helpful and friendly. They took our bags early in the day which allowed us to spend the day sightseeing.
The rooms were clean and comfortable, especially the bedding. I did think they were on the small side, though. Fortunately, the five women in my group were able to spread out between two rooms.
The hotel is in a convenient location to Chinatown, the Metro, and many restaurants. This does mean that there is more street noise audible in the rooms. We passed on a shuttle to Reagan National Airport and took the Metro to catch our departing flight.

This hotel was a very good deal via Priceline and met our needs for the one night.

The hotel is in a good location - within 15 minutes walking distance of the White House, Lincoln Memorial, Washington Monument, and Capitol Hill. The rooms are a bit small for the price paid, but were very clean and comfortable to stay in. The pool was closed, and the staff offered no apologies or alternate options, although the website claimed that alternate arrangements had been made. The lobby is nice, although the parking garage is dark and not my favorite place to be.

I visited Washington DC for business and stayed at the Renaissance. The company paid $200 per night.

If you are arriving at Reagan National Airport and you do not have much luggage, head straight on to the Metro station (subway) and catch the Yellow line (to Fort Totten). The subway will take you straight downtown. exit at the Chinatown/Galleria stop and you can resurface on 9th street. the hotel is a couple of blocks north on 9th and H st. (numbered st going N-S and lettered st going E-W) If you travel outside of rush hours, it's $1.35 for the trip.

On weekdays, the place is primarily for business travelers. I didn't see much in terms of families with small children. so it's quiet. the swimming pool is under renovation (during my stay around 6/08) Typical business hotel as seen in neon lights 9instead of incandescent) in the bathroom. the room is clean and a copy of USA Today is delivered every morning. there weren't really any features that make it distinct (like Embassy Suites layout and full breakfast)

Bring a good pair of walking shoe if you like to explore on foot. I saw a lot of kids with flip flops; those are not very comfortable for long walks. Some good chain restaurants nearby (Ruth's Steakhouse, McCormick and Schmick, Starbucks for your caffein fix, etc.) or you can walk to the Amtrak Union Station by the US Capitol and try B. Smith restaurant (if you prefer a non-chain restaurant) inside the station there are lots of fast food places.

Had to stay at the Renaissance WDC for a conference and booked the 'club' floor. Having just stayed at the Renaissance LAX, I thought I'd be getting something extra special on the club floor. No chance, tiny room. No instructions or directions on how to use the club lounge... nothing. A waste of money. I doubt I would recommend the hotel for any reason, it was without doubt, impersonal to the point of diffidence. Certainly NOT the experience I'd had at the LAX property which I cannot recommend highly enough.