I really liked the Saucony Freedom 1 and had to buy the Freedom ISO 2. This version suits me even better. The shoes are lightweight, incredibly comfortable and don't require a break-in period for me. I started running 4-6 miles right out of the box, averaging 4-6 days a week. Running on hard concrete/roads. This is an excellent shoe that breathes well, is lightweight and durable. All of this requires you to know your feet and your running style. This particular shoe works best for my arch height, foot width, and running style. Over the years I have learned that even the best brands of shoes may not suit the individual. As for me, I will most likely keep buying Saucony Freedoms until they change the style too much.