The breakfast area at Tysons Corner Marriott is not small. They usually seat around 80 for breakfast on weekends at one time with a separate area for Korean Air crew. The dining area extends beyond the immediate area adjacent to the lobby. As you walk towards the bar area, there is additional seating area to your left. They reserve part of that area for Korean Air crew, but there are also additional tables for hotel guests.

I just called the hotel, and they told me they offer a free buffet for gold and platinum members on the weekend. The coupons they give say continental, but they are good for the full buffet. I have stayed over 200 weekend nights at this property from 2006-2015 and have claimed the $100 guarantee for not getting the platinum arrival gift twice.