I stayed here again last night. My prior stay was on the 4th of July weekend.
As a Diamond the hot breakfast buffet is included, but it is a very simple buffet compared to the Grand Hyatt in D.C. It's served on the 2nd floor in the City House restaurant. There was no omelette station (overheard someone say that only operates weekdays) and only about 5-6 tables occupied when I was there after 8a.m. If you're looking for something basic for breakfast you'd be fine here, but if you want a selection of items the Grand Hyatt breakfast buffet has much more to choose from, as does the Capitol Hyatt.
Service in the restaurant was poor. I was offered coffee and juice by two different employees when I sat down (not a coffee drinker), and was not approached again until had finished two plates of food and was ready to leave (a span of 15 minutes or more). I looked around me and saw two other tables with empty juice glasses, also. My last visit in July I had very good service, so I'm willing to give them another try and hope today was just an off day.
I was in a petite king on the 14th floor which was the room I reserved (these rooms only have a shower). The room was spotlessly clean and appeared recently renovated. It also had an LCD television (maybe 37 inch?). Wifi is available in room through a Hyatt connection ($9.95 a day if you don't get it via status). It dropped off every 10-15 minutes for some reason (didn't do this last visit with the same netbook).