With how noise isolated the panel rooms are from the rest of the hotel, it shouldn't be an issue. I'm minorly concerned with possible noise at Registration; along with Autographs and the medium sized panel room (Hall of Magic) on the atrium level. Hyatt has added an additional pane of soundproofing glass to all guest rooms facing the atrium. Therefore, noise shouldn't be an issue if you're staying on-site in an atrium facing room and like to sleep in.
Speaking of breakfast and food and such, Knuckles Sports Bar has taken food duties from the atrium restaurant.
Here's their website's posted hours:
6:00am-12:00am | All day offerings. Freshly prepared on-the-go items
6:30am-11:00am | Breakfast Buffet, Chef’s choice of seasonal offerings
5:00pm-10:00pm | Dinner, ala carte menu
Bar Menu available between 2:00pm and 12:00am
Happy hour is from 5pm- 7pm.
http://sanfranciscoairport.hyatt.com/en/hotel/dining/KnucklesHistoricalSportsBar.html
The Hyatt will have a traveling food cart selling grab-and-go lunch items again this year on-site.