I would not use this smartshop for my weekly Sainsbury shop until they offered me £5 off my shop (early in 2019) for doing so. That was a big enough bribe, and I fell in love with the system.
No longer having to put everything in the basket, queue up at till, take everything out of basket and put on counter, then have to re-pack it in my bags.
Now, I use Alexa at home to make a shopping list which appears on my 'phone. As I scan items they go directly into the appropriate shopping bag (Fridge items in one, heavy items in a second bag. I do have to weigh fresh produce and then scan the print out slip. These go into a third small bag. All I have do at the end is go to the Smartshop (never been any sort of waiting there), and pay for it, then take to my car.
This has cut my shopping time each week by fifty percent, and with the shopping list - I have actually cut the expenditure each week.
I am coming up to 80 years old, but really love all this new technology.
PS: If you take down and scan something, and then change your mind for any reason, it is so easy to press the delete item button, scan again and it is taken off your list.
Once only I have had the random check, and even then the assistant only checked a few items in my bags.
I would not use any supermarket now that did not have this facility