Albert Heijn does this in the Netherlands, tied to your loyalty card. You can even import your shopping list and show it on the little hand scanners. At the end, you scan your loyalty card and it shows up on the self checkout.
I think it’s great, I get to go around the shop with a little laser gun.
An even nicer thing about the Albert Heijn self checkout is that I can use my own phone from start to finish. Connect to store wifi, scan items using their app (using the phone camera), pay with my phone (contactless payments) on the self checkout and use my phone to scan an exit barcode at the turnstile. My visits to the store usually last only a few minutes and I don't mind popping in multiple times a week.
Yes it's great. Put everything straight in your bag, no packing at the end.
The only thing I don't like is that they have added the option to the machines to scan all your things there instead of using the portable scanner. Which in my area has resulted in queues at the self checkout... Which used to be very quick when it was only used for the portable scanners.
I think it’s great, I get to go around the shop with a little laser gun.