Ive ben wearing frogtogs for just over a year now. and have only gotton wet on a serious downpoor once now. I just throw my poncho over the frog togs in serious storms concidering I still carry it ocasionally when heavy rain is to be expected helps keep pack contents and myself that much more dry. As far a a vapour barrier layer inside of a bag. ? when did we stop using trashbags for everything? In the summer months frogtogs stay at home i just pack a extra microfiber towel for drying the stuf that got wet under my poncho before climbling into my bag.