I use a euroschirm liteflex. It's incredible. It's the same as the 'Chrome Dome (they used to make them before they went bust) but a little heavier duty and a little heavier. I have the same hands-free setup mentioned above. I have an elastic loop and toggle on each strap. I only need one as it has it's own elastic toggle loop on the bottom of the handle.
It pings up and down super easy when you need it to and, because none of it is metal, you don't have the nightmare of it breaking or going inside out.
I would say to take a rain shell on top though. If you're exposed you might not want to have an umbrella up. When you're doing something practical like pitching a tent, hanging a bear bag, etc. you can't do it while holding an umbrella. It will also keep you from getting super cold if it's windy.