I bought these for experimentation on acoustic guitar and 6-string banjo,
the sound is a bit dead from the beginning, without the resonance typical acoustic strings produce and the feel is more dead too, out of the package it actually sounds and feels like 2 week old electric guitar strings.
It may be a solution for guitars with magnetic soundhole pickups, but I can't see any other use for them.
Quality is random, one thing I've noticed about all Pyramid strings is there's not much quality control happening, I've had all kinds of breakage and intonation problems with them, these particular strings intonate ok, but it's just a roll of the dice, after testing a whole lot of them I can't trust them anymore.