Meh - I was excited by JWO but it now looks like self-checkout will win because it works pretty well these days, and it handles all the corner cases including product sold by weight, large items, identical-looking items (common in grocery), etc.

With self-checkout, you don't need an account which is crucial for travelers. Self-checkout also supports cash for the unbanked.

I've tried SC in multiple countries, just hit the button for English, scan, scan, scan, weight, scan, scan, scan, checkout, touch my credit card, go.

Late night in Stockholm train station, I bought one bottle of fizzy water and checkout added 30 seconds or so.

Obviously, from place to place you sometimes get "rough edges" with mis-scans etc but JWO has its own problems.

I'm not even sure how much floor space JWO saves vs self-checkout.