Willow takes twice as long as Sally to eat the same amount of food. I looked at their teeth this morning (after some convincing and wrangling). Sally is the one with crooked teeth - Willow's look straight and normal, for cats. It kind of reminded me of all the reading I was doing on the Jacob Sheep's teeth (but cats have long sharp canines of course!)
J had a nice observance on this topic... "Willow chews."