Also stayed here in mid-October since Crystallized Marriotts were full......was surprised this major Hyattl was NOT part of the concourse system of shops and restaurants which connects most buildings in Crystal City. It was a rainy, windy day, so each minute outside counts --- here's a guide.
From the Metro station at 18th St South (along Crystal Drive), the enclosed walks head south through offices and shops and restaurants to 22nd or 23rd St -- including the Crystal City Marriott at 20th St and the Crystal Gateway Marriott at 19th St -- both easily walk-able from Metro station using the enclosed walkways.
The Hyatt front door is at 27th St and Crystal Drive, so there's a 4-5 block walk outdoors before reaching the enclosed concourse system. The Courtyard is across the street, further south of the Hyatt.
(here's a map from the Crystal City Central Planning Commission
http://crystalcity.com/_/File/_/crys..._site_plan.pdf
My stay on the rainy day was brightened by early check-in after a noonish landing at DCA.....and a corner Ambassador suite, with a cute triangular outdoor balcony, covered and with outdoor furniture. It was pleasant after the nearby noisy construction projects shut-down for the day. Indoor furniture was modern, almost "Hyatt Place"-like.
Free breakfast worked well with buffet in the main 2nd floor restaurant. Nice to have a breakfast area which is large enough for some morning privacy and quiet.
Shuttle to airport was running on-time and swiftly. Heard a few tourists complaining about wait for shuttle to/from Metro station.
(The Marriotts remain my favorite since they are much closer, walk-able to Metro station, and part of the enclosed walkway system.)