As a fan of the Guide 9, I was very disappointed in the changes to the toe box. I need a roomy toe box. I have plantar fasciitis that acts up from time to time, especially when toes get cramped. This is a main reason I was loyal to the Guide line. I had purchased 3 pairs of the 9's and loved them. The 10's are a totally different shoe. The toe is made completely differently and fits my foot like a Walmart shoe. The rest of the shoe is quite nice and there have been some nice improvements. There is a bouncier feel that seems to propel forward. And aside from the toe, the fit is comfortable. If toe room isn't an issue, you'll probably like the changes. If you have toe box issues, you'll want to begin the arduous process of finding a new shoe. Some have suggested getting a half size larger to compensate, but I've never found that to work. You just have a shoe that doesn't fit anywhere and somehow still cramped in the toe.