The new Scan and Go option is absolutely brilliant. You just scan the barcode with the app as you put it into your trolley and then pay on your phone, scan a QR code on your way out, and just walk.
Sometimes you get selected for a random spot-check before you can walk out, in which case someone comes over and scans 5 random items before you can go. But even with that it's so much better than old-school self-checkout.