When I moved to the US from Canada, I noticed there were a lot more of these self-serve checkouts. Very rare in Vancouver, BC Canada, though I see some places adding them in (Extra Foods in Park Royal in West Vancouver).
I don't like them. I have a hearing problem, and can't always hear the scanner beep as things go across the window, and have to constantly be looking at the screen to see if the item scanned properly, and then the computerized voice just irritates me like mad, because I hear only about half of it. It sounds like a nattering idiot to me, and doesn't always correspond with what's on the screen.
Plus, if you're staring at the screen to ensure the item(s) scanned properly, then you're not looking at where the bar-code is on the product... and blindly hoping you've got the item in question in the right position while you're checking the screen.
They really need to have on-screen instructions as well, with an option to disable that awful voice. By the time I get through one of these episodes (yes, it feels like some kind of episode), I'm ready to strangle the thing to get the computerized voice to shut up, since I can't hear most of it properly anyway.
Don't even get me started on the automated phone stuff. It's like, "Press 1 for gibberish, Press gibberish for customer service, gibberish gibberish shipping, press gibberish for gibberish...."
Ok - now I've gone off topic....sorry 'bout that