I got the UK size 6 (Europe 39) and in my view they run true to size. It took a while to break them in (had to wear two pairs of socks for two days to wear them in around the house) but I think they'll be comfy once they're completely worn in. So far I've only worn them on the street for short distances since they're still new and I want them to feel completely comfortable so I don't get blisters. Not too worried about getting them dirty - I don't war them in the rain.