Extremely comfy even right out of the box. I didn't feel I needed to break them in, but did feel them loosen up (I have had boots that kill my feet and ankles for weeks, not these). Only problem is I hate Gore-Tex they don't breathe what so ever my feet sweat even just sitting at work. These are great definetly recommend them I almost feel like they would make a good trail running shoe. I have narrow feet and usually wear a size 12 in most regular shoes and got an 11..5 or 45 and they are perfect. If you have wide feet these might not fit very good.