Hello, I was surprised to find Sun Country IAD Terminal to be nice. It's a low-cost carrier, so I didn't have high hopes, but check-in was quick and TSA lines were moving quickly. The terminal is not gaudy, but it is clean and efficient. There are some spots to get coffee or snacks in the area, and employees were friendly. Sun Country has done a good job of streamlining their Terminal process. The gate wasn’t crowded, and the boarding announcements were clear. If you’re looking for a simple, low-hassle departure, it does the job.