Perma-clean, endure elements, like light for sleeping, & decreased ACP. Can't think of any reason why an armor wearing fighter would not buy this quality. Which kinda makes me wonder but I'm not always a good judge of these sorts of things.
Yeah, considering it costs more than a suit of straight up +2 armor I think it's fair. It's not a situation that comes up all that much (neither Pari nor Kalinn's ha it happen in their entire career).