I use circle-K because it's like 3 blocks from me. The self-checkout seems to work fine. I buy alcohol on the rare occasion I drink, and even then the cashier just steps to the side for one moment to check my ID, presses a button, and then goes back to what he's doing with someone/something else. It never overcharges me, at least, and it always seems to pick things up in just a couple moments. I suppose I take the time to space them out a bit, but I always seem to have a perfectly reasonable experience.

That being said, I see the same one-person-two-registers thing at 7-eleven, and it's very, very fast.