We had points that we had to use or lose, so we used them to stay at the Mandarin Oreintal (in Washington DC). The hotel was very nice, but parking was very expensive - $49/day if I remember correctly. We looked at it as getting a really nice hotel for $49/day.
There weren't a whole lot of dining options in the immediate area, and it was about a 10 minute walk to the nearest metro station. It was also about a 10 minute walk to the Smithsonian/National Mall area.
The room was huge, all marble bathroom, high quality linens and a comfortable bed. The pool was a smallish lap pool that wasn't open terribly late. I was there with my DH and 2 DDs. Not a lot of children staying there (not surprising) but the kids had a good time. We stayed in a preferred/water view room. It had an ok view - our window faced Alexandria.
If you have points you need to burn, I recommend it. I would not however pay out of pocket to stay there - we could get something with cheaper parking and closer to the metro for less money in Alexandria.