This was our third trip to DC in five years but the first time we didn't stay with friends. We chose this hotel for several reasons: location, price (got an amazing AAA rate- less than $100/night over the 4th of July!) and trusting the Hyatt brand.
We were very happy with the hotel. We were happily surprised upon arriving at 10 a.m. that a room was ready for us. The front desk staff was very friendly and helpful throughout our 5-night stay. The room was not huge but was certainly decent-sized, the bathroom was much larger than typical hotel bathrooms and it was all kept very clean.
Two minor negatives- we never recieved the extra towels or robes we requested both through the e-concierge and the front desk. Our refrigerator didn't work at first but when we advised the front desk of this, they sent up someone from maintenance who got it fixed for us right away.
As everyone has stated, the Rosslyn Metro stop is very convenient to the hotel. Be advised that you do have to walk around the hotel (the main entrance faces away from the Metro stop) and cross two small streets to get there. We felt very safe walking from the Metro to the hotel, even after dark. The area is well-lit and busy.
We did not dine at the hotel but did check out several nearby restaurants, all of which were very good.
A couple tips- keep in mind that this is a slightly less fancy hotel, even for a Hyatt. It's not all gleaming brass and wood with employees fawning over you (but considering the prices here compared to downtown hotels, we didn't care!) And, if you can, be flexible with your travel dates (this applies to almost any hotel, anywhere). We found that by arriving on July 1st instead of June 30th, the price dropped by almost $100/night for our entire stay.
In all, this was a great experience. The prices are much lower than hotels inside DC but it takes almost no time to get into downtown on the Metro. We would absolutely stay here again.