You know i thought this could be a very different discussion with leather and rubber in the title, shame, but i do have an oppinion. I am not a fan of rubber on expencive watches, ruber to me always looks? well? to GSHOCKish, i tried a PO on rubber and i never really liked it, but on SS i loved it, so for me it would have to be leather or SS, if i was after a very work like strap i would have to go with kevlar if one was available.