I bought one this spring, just to see what all the fuss was about. After all, it looks great on paper, and there's something serene, and a maybe a little romanticized, about being dry under the pitter patter of an overhead shelter. So being a very wet spring so far, I tested it out when I went to check mail one day. It's only about 50 yards to the mailbox, but what a struggle! Even the slightest breeze would try to yank it out of my hand, or throw it off my shoulder. Walking back, I had to point it out in front of me, forward off my shoulder, just to not feel like I was walking uphill with a parasail dragging behind me.
I couldn't imagine wrestling with it in an area with swirling or changing breezes. It would take some really, really calm weather to even think about one of those fastening, no-hands systems. Now obviously there's a learned skill involved here, that I clearly lack. But as a first time user, I thought I'd throw out my first impressions through a set of "new eyes". I purchased the silver topped version, for sun use too, but I'm sure rain or shine is still the same effect. Needless to say, YMMV.
Edit: The lite-flex was the one I purchased as well.