Huh, I always thought it was the opposite: If you're in a hurry, you go through traditional check-out. Nothing really matches the speed of an experienced and trained grocery store checkout clerk whizzing boxes past the scanner faster than you can load them into your cart. I think traditional checkout can blaze through 30 grocery items before I can even get three or four out of my cart, fumble around with them in front of the scanners, and then get chastised and stopped by the computer because I didn't place the item properly on the shelf next to the checkout machine.