Last time I was buying Levi's I picked up two pairs, checked fit with one, just grabbed another. Getting home I tried the other pair and found the fit radically off. Took them back, intending to exchange, figuring it was a one-off labelling error or similar. Nope: I found maybe two more pairs in my size, but neither of 'em was remotely close, and the variation in different directions: too loose, too tight, leg length. Gave up, stuck with the one pair.