I thought about this today when I was trying on hats at the store. If you really want to know how much a quarter of an inch difference makes in girth, take an adjustable baseball cap, the one with the plastic at the back of the head, and move either 1 peg larger or smaller than your regular hat size. Notice how now it's either much tighter or much looser? And that's on a 22-inch head, on average. Imagine that difference on a 5 inch penis. I'd welcome females opinions here, but I'd say that after thinking about it that way, even a quarter-inch of girth is HUGE in making a difference in feel.