I've owned a pair of Simms Rivershed boots with felt for nearly 3 years. They have a LOT of miles on them, and I bought a pair of Riversheds with the Vibram sole not too long ago. I used them today for the first time, and was amazed at the grip. There are some things that should be pointed out however. The felt soled Riversheds were stiff as a plank when new, and scared the h$ll
out of me. Size 13 boots that do not flex at all are worse than wearing the box! They loosened up after a few weeks, and served me well on some tough rivers and streams. The Vibram soled Riversheds were equally stiff, but I knew what to expect. I took them to the local stream, and to a spot that is covered in thick hairy brown moss over green algae. The stream bed is one large sheet of rock, with rocks and and boulders strewn everywhere. The current was swift, and the ideal place to test the Vibram. After
a couple of hours of trying to find a reason to hate the new boots, I determined that they were just as good as felt, and grinned. I then turned to head for the bank. What followed next was a series of pirouettes, and cork cleansing fist clenches (when the grip gets
wet, and your hand opens and closes frantically leaving the cork shiny clean...LOL!). I managed to stay upright in the waist deep water, but slammed my knee HARD on one of the cooler-sized
rocks that litter the stream. I immediately blamed the Vibram, but then flashbacks of the same type of slip while using the felt Riversheds poured through my mind. After determining that I hadn't broken my patella, I resumed fishing and enjoying the new boots. I did make certain to bring my wading staff along, as I was certain the Vibram would not perform well. I only used the staff to cross a treacherous section of the stream: waist deep, uneven bowling ball sized rocks, and a current swift enough to put a deep bend in my 3/4" Folstaff! I had tried to cross this section yesterday afternoon, but decided it was too crazy. It was still crazy today, but I was product testing. No problems beyond being nearly swept away! I won't be ordering cleats for now. The Vibram gripped WAY beyond my expectations.