I bought a pair of Endura ones about 15 years ago. They lasted quite a long time until one of the zips went. I replaced them with some Altura ones, and then about 2 years ago one of the zips went. Since then I've been wearing one of each (determined to get my money's worth!) but another zip has gone so a replacement pair of Endura ones are on order.
I don't see much difference between the quality of them, each pair was just what the (same) lbs had in stock at the time. BUT do not be fooled by the sizing. I did buy a pair of "large" Endura ones earlier this year. They are not large, and would not fit on to my size 9s, hence the extra large now being on order.