It is the only choice that really changes the sandal. Everything else on this page — quick-dry uppers, arch support, lugged soles — comes as standard.
For trail with loose rock, roots and scree that finds bare skin. Heavier and warmer than the alternative, and the one you want on a long descent.
Drains and dries fastest, coolest in heat, and easiest in and out of water. Wear it where nothing is going to kick back at you.
Most of these come from one maker with near-identical listing titles, which makes them impossible to tell apart as a wall of cards. So: a table. Toe type and terrain are read off each listing. Every row opens Amazon.