I've had it for two years and have used it a lot, mainly out in my inflatable canoe on rivers and in the sea, but also in heavy rain at festivals. Its been very wet, many times and my phone has never had a drop of water on it when I've taken it out. It has three separate seals at the top rather than just the one of the reviewed product. It also comes with a lanyard.
I would suggest to anyone who buys one of these for boating of any sort, whatever the make, to attach something buoyant to the cord. A dry phone is no use at the bottom of a lake.