Hi Bruce,
Kevlar is a pain in the a$$ to get clean edges after sanding on them.
Kevlar is cheaper, easier to layup, weighs the same as CF. It's plenty strong. I don't know how it compares to 1/16 ply.
CF is really easy to use in the cured sheets and you can get a razor sharp edges on the running surfaces that hold up.
I cut kevlar with sissors, but after that you are stuck sanding it down and and the fun begins.
I cut CF with a dremel cutoff disc.
My opinion... CF, Kevlar, fiberglass, plywood it's all good and plenty strong for R/C boating. Just build something you will enjoy. (I would start out with CF)
-MikeP