I also had trouble with the Kentreks. I really wanted them to work, but just couldn’t get to a comfortable place. I went with the Crispi Guides and absolutely love them. No problems. Bottom line though, everyone’s feet are different and you just gotta find what works for you.
I really struggled with my Kentreks because the soles are so narrow and tall. It felt like I was expending extra energy, both physically and mentally, trying to balance on rough terrain. I really wanted them to work. Switched to Crispi and love them!