I am very disappointed in the Guide 8.  I previously owned 3 pairs of Guide 7 but I was determined to make the Guide 8 fit right.  I tried 3 different pairs and they all fit the same.  Not much cushioning and my right heel slipped out for some reason.  I even replaced the insert with a more cushioned one but it didn't help.  Should have sent the 3rd pair back too. I never had any problems with the Guide 7.  I could wear them right out of the box.  What changed?