I bought size 38 (US 8) and wore them everyday on our trip to London. Lots of street walking, up and down stairs at The Tower of London and in the subway.  On average, we walked 7 or 8 miles but we did 12 miles on two of the days.  My feet did swell but I just losened up the shoelaces at bit. I recommend you get really good socks if you plan to walk a lot.  I bought Carhartt Performance Force socks.  I brought my orthopedic inserts but did not end up using them.  Feet hurt and swell when you walk as much as we did but it was overall and not focused on my heels or arches.