I think Kennetreks are just like any other boot, i.e. they have to fit your feet to be comfortable and some folks feet just aren't made for them. For example, I have Salomon's, Crispi's, Danner and Meindl and all fit well. Today I read about a special on Asolo hikers so stopped by Sierra Trading Post to try some on. Well, 50 feet of walking in the store convinced me the Asolo's would not work for me. I had lots of heel slippage which would certainly translate into blisters in short order. That boot just isn't made for my foot. Best suggestion is to see if you can try several different boots or contact Lathrop and Sons for customized foot analysis.