Thanks guys. I have an old pair of felts (probably a couple) but wanting to do my bit to fight didymo, I went for Vibram several years ago. For Christmas this year I got a pair of Simms Vapor, the new lightweight hiking boot style, and those are the ones I'm considering for spikes or cleats.
My older pair of Vibram w/o spikes will be fine for the Caney - anything works there.
I guess my most frequent falls are on angled slabs. Got a bad dislocated shoulder at Cataloochee a few years ago when my feet slid forward and I sat heavily backwards. Then again I had a pretty bad fall last year at Cataloochee (is there a pattern here?) when my toe missed its grip stepping up to the bank and I went down on one knee, hard.
Seems to me that the aluminum cleats that Silver suggested may be the most effective for my situation. We will see...
The mass of men lead lives of quiet desperation, unless they fly fish... with apologies to Thoreau