I love 505s but I've found that if I order 3 pairs, all three will fit completely differently.  The faded jeans tend to be really tight and low cut so that they barely cover your backside, the traditional stonewash seem to have the truest fit to the original 505s and the "trendy" washes I've bought are all over the map. I've stopped buying them online because I have to keep sending them back. It's a lot easier to wait for a sale locally and go try them on.