I tried them a few times in various stores, then gave up and avoid them like the plague. They do NOT work, in my opnion.

"Put item in bag." I already did. So I take it out and put it in again.
"Unknown item in bagging area." It isn't unknown, you just scanned it!
"Please wait for attendant." Who? Where? When is this attendant going to materialize? I thought this was a quick check out procedure.

After ages and ages, attendant arrives.
"I'll have to void you out and you can start again." Uh, but I already did all but the last item.

Coupons? "Oh, we don't take them at this line If you have coupons, you are really supposed to go to a cashier line. I can send you to customer service with your receipt and they will give you a refund for the coupons. You need to pull out the items so they can see them."

Marked down baked goods? "Wow, I've never seen these before are they good?" I won't know until I get OUT of here and go home and try them!!!

UGH! No thanks. The technology just doesn't work.