I like them for just a few items, but really if you have more than one bags worth, you are in the wrong line.
My sons work for a major supermarket chain. To be honest, those newer checkers are probably only making a bit over minimum wage when you deduct union dues. The baggers are making less than min due to the dues.
They kind of feel the same way, use the self check if you have 5 things, more wait for a checker.
At our local home depot, we have a super helpful clerk, always pointing out something extra to sell you and telling you about most everything in your cart with something to up sell you. I am sure management loves her, but I would rather scan a pallet load myself than wait in her line if I am in a hurry. (I spend way too much time at Home Depot as it is! and I already know what I am buying. Today she was telling me not to take the toilet seats out of the plastic in case they did not work out for me. Hello I am buying a dozen at a time...you think I dont know what I am doing with them? Property Mananger)