I had the wave inspire 6 and they were a great running shoe.  I was excited for the wave inspire 7, but was disappointed very quickly once I put them on to go running.  They were not the most comfortable, especially around the ankle.  In fact, I bought another pair of 6s because I didn't like the 7s. When it came to the wave inspire 8 I was weary because of my dissatisfaction with the 7s, but because of how good my wave inspire 6s were, I decided to give them a shot.  The 8s are better than the 6s, and much better than the 7s.  I am very satisfied with the wave inspire 8.  It is very comportable, and a solid running shoe.  When the pair I have are worn down, I will not hesitate to buy another pair.  Great shoe!