I guess I should have said "Listen, smile, and nod."

There are certain topics where people are just waiting to leap at the question no one asked. This is one of them. Panniers are good if you want panniers. Backpacks are good if you want backpacks. I don't know why everyone seems to think they need to immediately tell someone asking for a backpack that they don't want a backpack as if they had never heard of or considered panniers.