I rarely shop at Walmart any more - maybe once or twice a year. But I usually use self-checkout.
I shop at our Walmart Neighborhood grocery store a lot - I love that place (new, clean, fast, cheap, perfect size, etc.). The self-checkout there is a dream...it actually works. I haven't been to the local Kroger in almost a year now. It's much more convenient location-wise, but they usually only have one cashier and their self-checkout is awful. I would get through an entire small set of items without "ATTENDANT HAS BEEN NOTIFIED" maybe one out of ten times, and I got tired of having to wait 30-90 seconds for an attendant to come clear whatever idiotic error it had detected (and it would happen about every other item).