Neil Alexander R.wrote a review of La Sportiva Katana Lace Vibram XS Edge Climbing Shoe on April 23, 2016
Familiarity: I've used it several times
Fit: Runs large
First off they take a bit to break-in. I'm a size 8.5 US in street shoes. First pair I got off ebay at size 38.5 which is the same size as my comfortable pair of Katana velcros. Could barely get them on my feet after a weekend of climbing since my feet were swollen. They broke in to be pretty comfortable. Can wear them for a 30 minute pitch no pain. Definitely a tech fit and I couldn't go any smaller.
Bought another pair here, at size 39.5. Still needed a break-in period on a week-long climbing trip. Lol. Now they are super duper comfy and they will be my everyday shoe. Time will tell how much performance is lost because of sizing but I think they won't stretch too much really.
These are very low volume shoes when you get them but they expand in volume and a bit in width so as to fit like a glove. My tech fit size fits better in the arch but I bet the comfy pair will conform to my highish arches before long.