Flying on DL, especially if I was alone and had no luggage to check, I'd opt for the kiosk. That wasn't always true but I have gradually learned how to change flights, seats, and add myself to the upgrade list. The last item is important because too many times when I relied on an agent to do that, they did not. It's sad, because I prefer to interact with humans and don't want to see these people automated out of their jobs. When the task is mundane, if you want it done right, do it yourself.