Now a days they are putting more spandex into jeans. I don't know if they way they weave the demin is different, but I have a pair of 550's that I love to death...fit well and comfortable, but they were starting to look ragged.  I purchased these.  The fit is much longer and the spandex makes the waist stretch out of shape.  Now, that feature may be welcome when eating a big meal or sitting through a long car ride, it's not appealing for general wear.