I have a Framus 12 - zero fret, bolt on thread-through bridge, tone-robber adjustable saddle, plays wonderfully but almost no tone at all. I suppose I could put a woodie or something in the soundhole and use it when plugged.

I know a man - no names no packdrill - who has a Framus 6 which he assures the world is VERY rare and worth megabucks, but it has all the tone of a scaffolding plank and since it has an uncambered fretboard, equivalent playability. I once borrowed it (since I was without my own guitar) to do something in a funny tuning and it took me 20 minutes to achieve a compromise tuning that would play close enough in tune up the neck.