I have a pair of Keen Clearwaters (similar to the ones in the OP, but a bit more open). It's one of the best footwear purchases I've ever made.
They don't soak up (much) water.
They're light.
They have a fairly stiff stole.
I bring them along when hiking. I use them when fording deeper streams (great for protecting against sharp rocks etc and dries quickly) and for lazing around camp.
I also use them when sailing: on deck, having to wade for mooring purposes, or when walking on an island. Also great for playing around by the sea, again due to protecting for sharp rocks or mussels etc. They also float well.
They wouldn't be my first choice for walking all day, but I have walked fairly long distances without discomfort.
