You and I are in complete disagreement; I find the self checkouts are far, far slower (apart from the relative line waits). The irritating pause between each item is 2-3x longer than the cashier's, you keep getting lectured on "ITEM IN BIN" if you didn't move something the extra inch, and then they keep trying to give me cash back or other things which I just don't care about.
I remember once in Home Depot, I was buying an extension cord, and since they had decided that there should be NO human cashiers at that time, and I spent a few minutes looking for the damn barcode. I finally found a service rep, asked how I was supposed to scan the thing, so he proceeds to rip the packaging open to show me the barcode INSIDE the packaging... how the hell was I supposed to know it was there?
God how I loathe those things. If they just used them as additional* lanes, I wouldn't mind, but in every case, there's suddenly significantly fewer human cashiers.