I use the one situated in Seattle, Amazon HQ. It's just like self-checkout at a grocery store with fewer steps. The entrance/payment mechanism is Amazon One (a palm scan associated with a payment wallet). At Whole Foods, it's used as an optional payment option at checkout.

It's convenient; I only ever remember one problem where it thought I had purchased an item that I picked up and decided on something else. I disputed it online and it was resolved in a day.

> I disputed it online

Oh man this is what consumers would love to do, have to constantly adjudicate false positives online which they'd have to track to make sure didn't happen. What nonsense.