I've only had them for a few months, but I've gotten quite a few rides in them. After the first wash, the stitching that holds the chamois in place is already coming undone. Also the fancy little scorpion decals on the knee and butt are about to come completely off (not sure if I care, tho). Probably not a bad idea to step up to a more expensive bib.
It's important to note that these tights are not insulated at all. Aside from the extra coverage on your knees, they aren't going to keep you any warmer than your summer shorts.
Fit is nice. I'm 5'10"/175 and I got the Large.