I, too, wondered whether you could hike in some of these "sandals." I thought about trying it but have decided against it. I am going to give the off road crocs a try and report back to you, probably later this summer. Here is a link to them:
I just couldn't justify spending nearly $100 on wading sandals like the Simms or on Keen's when I know that I will wear them so little. These crocs, I can see wearing a lot, and they're only $39. Probably not as sturdy as other sandals, but they will stay on because of the strap and they are lightweight. After I buy them, I will post the weight.