Having been to DC over a dozen times, I agree with the other posters here that having a car during your whole wouldn't be a good idea....traffic is bad and parking is worse.

DC is a nice "walking" town for the most part. And yes, the Metro is a GREAT mode of transportation. Not only is it convenient and reliable....I absolutely love their architecture with their stations. Very nice in my opinion.

With regards to hotels, I've only stayed at the Ritz Downtown, Grand Hyatt, and Westin Embassy Row in Dupont Circle.

The Ritz is ok. They don't have a gym/or pool onsite. They do partner with a local club there.

I do prefer the Westin for it's location in Dupont Circle. More shops/restaurants etc.....just more convenient in my opinion.

I'm staying at the Westin Embassy Row the beginning of June and the Ritz for the last couple nights of my trip. (Only reason I stay at the Ritz is that my company pays for it.....but since I wanted to stay longer....I stay at the Westin for the rest of the time...)

Feel free to pvt me to see how my trip was Last time I was there was last August....so it's been a while. We'll see if anything has changed since then.

Good luck with your trip! A week is a good amount of time in DC.....you might not even get to see everything that you want to see in that short amount of time....