Buying jeans is the classic YMMV situation, involving lugging stacks of jeans into dusty dressing rooms.  Even jeans labelled with the same size can vary noticeably.  Amazon has made the process simpler by offering a wide variety, free shipping (at least for Prime) AND free returns.  So I suggest you order some of these in a few sizes AND some 514s in a few sizes, because there's no way to know if they are going to fit the way you like until you have them on your person.  In my case, I guess my rear is smaller than most because the 512s are baggy there more than I would like.  Not what I expected from the product description.  I kept a pair just to have some knockaround pants, but I think from now on I'm a 514 kind of guy.