I was lucky to be loaned a much larger pair of these sandals while on a walk in the desert, after my boots gave me a blister. Even though they were large, they were so comfortable and gave me no grief. The advice of the owner (it was hard to give them back!) was that the leather ones were more robust and perfect for the harsh desert environment we trudged almost 30km every day. So when i got back to my computer, the first thing I did was to order my own pair and I took time to estimate my size by adding a half size, as I saw was advised. They've been perfect for the muddy mountain walks I've been taking and look forward to using them out in the desert in the next month.
They haven't been really tested yet, but my feet with PF actually feel ok in them! Didn't even need an expensive insert, which could be tricky for this type of shoe anyway. Love them so far, but will tell more after holiday in NZ.