I hesitated to say anything about my experience with heavy wader boots, but decided to do it anyway. Several years ago, I bought a pair of Simms boots with leather uppers an felt soles at the recommendation of the shop owner. They were good boots, but got very heavy after a few hours wading. With a bad right leg injured years ago, I thought I needed lighter boots so purchased another pair of lighter boots. So I purchased a lighter pair with rubber soles...also Simms, and tried wearing them for a while. The River I normally fish is fast water, but not real rocky. I found that the current was causing me to loss balance went I lifted the right leg. I fought it and increased use of a staff until one day I went back to the old heavy boots. To my surprise, I found that I was much more stable with the heavier boots. When I lifted my right leg with the lighter boots, my foot didn't always come down where it was supposed to because of fast current. So unlike some, I use the heavier boots and feel safer doing it. My 2 bits worth on this topic.