I wore this for the first time yesterday.  It was comfortable, stayed in place and my keys and iPhone X were still there when I got home from my walk.  My phone was in a thin rubber case and it did take some stretching to get it past the zipper, but plenty of room once in.  I am glad there is a clip for the keys because there's only the one zippered pocket.  I did not flip it as I wasn't carrying cash or cards, so cannot speak to the reliability of the non-zippered slots, but I imagine when flipped all would stay in place.  Very handy for warm days when a jacket with pockets is out of the question!