We wanted to avoid traffic near the Mall in DC without paying 300/night and this hotel seemed to work. We were just there for one night and before we even got the room key we were using the shuttle around noon: They offer a free shuttle service to the metro station and when you return, you simply call them to shuttle you back. It works out well as the Metro for my wife and I cost around 13 a day.
The room was clean and comfortable. I had one of the best nigh's sleep in years. We ate breakfast in the morning which was pretty good for a hotel breakfast. Our only issue was a sluggish internet connection and it's still rather pricey for a Tuesday night ~180/night, but it is July...the busy season.
I'd definitely use this hotel again, but I think the you're better served to visit DC in the cooler months due to both the costs and the walking you do to see the attractions.