Sizing on these was hard - I had to get a couple sizes before I got the correct one.  Every site said something different about them being too big or too small.  I wear an 8 in most shoes (an 8 1/2 in my Nike Free running shoes but I like those big) and I settled on the 38 in these.  I didn't want any extra room - really wanted them to fit like gloves so when I am going downhill - my big toe sometimes hits the end but it is not at all a problem.  I have run roads in Nike Frees (5's) for 2 years - nothing else, but they just picked up too much of the trails in the treads and I felt that there was too much extra shoe.  This shoe kept the minimalist feel that I like and added a really great grippy tread.  Since I am used to the neutral/minimal shoes, I didn't take time to break them in slowly - but if this is your first time in this type shoe, you likely want to take them for short runs first or you're going to get sore calves.  No blisters when I took them right out of the box and ran for 1 1/2 hours.  I will wear them with socks - they're not super breathable so my feet got sweatier than usual.  In the winter, they will probably be perfect and for now, I can handle a little sweat. Love the navy - they're a great looking shoe.