My husband and I love to hike and these boots make it more enjoyable.  Other reviews were right on- no break in time is required and they are very comfortable from the first time I put them on.  I was a little concerned about hiking over rough terrain because they are so light, but they worked out great whether I was walking on a blacktop road or hiking through rough trails in Tucson mountain park on our last vacation.  I've always loved other Merrell shoes and these boots are a winner too.  I normally where a 9.5 shoe, and the 10s fit perfectly to allow a little heavier sock for hiking.