I've been serving in the Peace Corps in Vanuatu since October 2003. I had Tevas before, but they fell apart quickly. However, these Chacos are great. I had purchased the Z/1 model but they were a little bit slippery climbing over wet surfaces, as the island I was serving on was full of waterfalls. I bought the Z/2 to go exploring around Australia and after abseiling down canyons, climbing high summits, etc. these sandals feel great and they don't feel as if I would slip off the wet rocks. The Z/2 is much better for climbing over wet surfaces but if you're into long walks but not getting wet, then the Z/1 has much better treads.