I stayed at this hotel a couple days after christmas, and thought the stay went fine. There was a little bit of hammering from the construction in the morning, but it didn't wake me.
I booked the AAA rate, and they asked to see my AAA card which i didn't have, but i did have a printout of my membership confirmation. as i was getting it out, the front desk agent just said that it wasn't a big deal, and gave me my room keys.
The room was nice, it was an atrium suite on the 1st floor (i used a suite upgrade cert). Pics are here:
http://www.acetravelreviews.com/Hotel/DC/grandhyatt.pdf.
I didn't have any problem with the tv signal, but the tv in the parlor room had a remote that didn't work, so as i was walking out i told the front desk agent, and when i got back there was a new remote.
overall, staff was very nice and helpful and the metro being under the hotel was great