My girlfriend works as a retail cashier and she was lamenting her company's switch from an AS/400-based checkout system to a more modern GUI. We're only 20-somethings and she's far from a computer expert, but she recognizes that taking a bit of time to learn keyboard shortcuts and terminal commands ends up being much quicker than using a mouse or even using the tab key to get through forms.

Her company's reason for the switch was making it easier to train new cashiers. I'm expecting they'll see a net decrease in overall cashier speed though.