Having a trained cashier quickly scan your items for you does indeed beat fumbling with the scanning process while the GLaDOS built into the register judges you for not doing it properly.
Yes. And then you look at it funny and it exclaims, "unrecognized item in the bagging area", and asks you to assume the party escort submission position, while it fetches the party associate clerk.
That's why the app is nice; it's on my phone, I do it as I go along, and there's no scale involved. Faster than both self-checkout and cashier, in my experience, especially on a busy day.
