Barry's missionary zeal converted me to sandals last year. They are great for stream crossing. I pull off my socks, put the sandals back on and cross. Then I walk for a while sans socks until my feet are reasonably dry. Then I put the socks back on, replace the sandals, and keep going.

I used to use crocs (flip flops are a similar idea) but in swift current it's easy to lose one off your foot. I sandals I don't worry about this and I have plenty of traction.

In colder weather I use sealskins and sandals to cross streams and then switch back to my wool socks on the other side. I'd use sealskins and sandals all the time but they keep my feet a bit too moist from sweat I feel. Not super bad but not good enough to wear all day.