Several years ago I bought a pair of Arizonas with thick leather. I wore them to a wedding. Didn't do a lot of walking, but man, by the time I got home my feet were badly blistered and hurt like hell. I wore them off and on for brief periods for about six months, often with socks because the leather was so stiff, and eventually they softened up. Nowadays they're my most comfortable pair of Birks. I can wear them for hours--and days and weeks at a time and my feet feel great. There's definitely a break-in period.
Worth noting is that I developed a mallet toe because of my Birks. One of my toes was always clenching the footbed. I went to a foot and ankle clinic and got x-rays. There's a bunch of things wrong with the toe, including joint arthritis and permanent mallet deformity. Don't have those things wrong with any other toes. I'm convinced it is due to the way my toes were clutching the edge of the Birk footbed.
That’s interesting. I tend to agree….although Birks claims to be “orthopaedic” (whatever that means…it sounds good for the feet), I’ve heard the argument that truly the healthiest way to walk is barefoot. Thus barefoot shoes and sandals are becoming more popular - zero drop, minimal cushioning, wide forefoot so toes can splay.