bottom enty is the way to go. it has a slight learning curve but its makes life simple with its fast and easy with one step closure cuz your body weight does all the work
one set back is if you plan on getting and under quit for insulation it is a pain to adjust.
i do recomend the ss sold by hennessey as it keeps a 3 season set up very light and fast. i would order from the hennessey site just for the free snake skins and there customer service is great