Very comfortable from Day 1 - did not need any breaking in.  Naot sandals are my favorites.  Size 38 (7.5)  always fits me perfectly so I can order them over the internet.  These are very pretty - I was having trouble finding a delicate and pretty sandal in white - but also feel very sturdy and comfortable for walking.  They are also nice and light for packing  and don't take up much room in a suitcase.