With few items, I can be in and out in a minute and never have to wait in line because there are so many self checkouts. If I have a lot of items, then I can wait in line for cashier because scanning all of them is more work than I care for.
I rarely have issues using them, at a variety of retailers.
Easily, the best self checkout I’ve ever used.
It's a really quick way of doing checkouts, i.e. you pretty much just walk out, unless you bought alcohol, in which case you'll need to wait for someone to check that you're 18.
My main issue with it is that it makes shopping terribly slow and mentally stressful. The whole process of scanning items as you pick them up is less convenient that you'd think. Some items, like vegetables don't have barcode... now what? I found myself constantly checking that I've scanned everything and focused more on the app than anything else. It's a great way to ensure that people only get what's on their shopping list.
Except for the fast checkout, which is really nice, I can't recommend it.
Sometimes though, when all the checkout lanes are in use, I dream of a licensing scheme for use. So many people take _forever_ to checkout, you would think this technology was introduced in the last month.
When this happens I like to play a game where I race to check myself out before everyone else (that has already started since I am taking the latest emptied spot). I would say I win this game probably 80% of the time.