Like 'em or hate 'em, we're all going to be learning to love the rubber soles and I think felt is going a thing of the past soon. New Zealand outlawed felt soles at the beginning of this season. Several US states are considering doing the same.

I won't be replacing any more wading boots with felt soles. I have one pair of Aquastealth
Simms with studs and I use these for my winter boots. The primary advantage I've found is you don't get ice buildup on the soles as you did with felt. This was a huge problem in the winter and stepping on ice with frozen felt soles is absolutely leathal.

On slippery rocks where traction CAN be had (so not including that obsidian out west in places like the Umpqua and forth) I've found AS and stunds works fine. Maybe not a good as studded felt, but acceptable. I'm not looking forward to trying AS with no studs, but that day will come. Hope it works.

Grouse