I recently returned from a trip where I just about broke my neck, multiple times, wet wading in some Columbia water-shoes that were pretty much intended to be worn around the pool.
Yes, there's a piece of cloth that goes between your big toe and the rest of the toes, but it's thin and you hardly notice. My booties have a semi rigid toe box, enough to protect your toes some, but the rest of the bootie is soft neoprene and I wouldn't use them to wade I rivers with good sized boulders or rocks.
For walking around, they're great. I walked all over that valley for two full days and my feet never felt tired...like walking on an earth of memory foam. I would be worried about how they do hiking on steep inclines, though. They are built to leave room for your feet inside the shoe for water to easily release through the vents...on steep mountain inclines hiking up or down that could cause a problem (I'm speculating here) with feet slipping inside and causing blisters. As an example for Yellowstone, hiking up and down Slough Creek trail to and from the meadows might be better to have a snug fit hiking shoe instead of these. However, once you're up in the meadows there, these would be great.
