I tried all the soles for the Korkers and these are the best.
I fish the Umpqua river with big slick rocks and fast moving water and these have plenty of traction, they get better as they wear.

I've been using straight up felt until a guide set me up with studded overshoe things and they were a revelation. After much deliberation I picked up a set of these and love them.
I've used them for a couple of months before posting this because new felt is always wicked grippy.
These are as good as the day they came out of the box and I haven't found a situation where I felt I needed more traction in northeastern freestone streams and rivers.
I'm careful to clean and dry them after each use and still feel good about myself when it comes to invasives.
I'll be picking up another pair for my big winter Korkers. Great soles.

This is a great sole, and it's been working well for me on mossy freestone rivers. See my review of the Metalhead boots for more info.