There is any disadvantage in using non-wound materials for thicker strings?
Hello again, Fernando. This question of yours goes straight to the crux of the matter. Yes, there is a disadvantage in thick non-wound strings. It is why wound strings were invented centuries ago.
Take any string set you have, and unless it is formulated with some really out of balance tensions, you'll notice the thinner strings are clearer and brighter. The thicker you go, the less clear, less bright,
less responsive, the string becomes. Sooner or later, depending on the material, you hit a threshold where it becomes pretty much useless as a musical instrument string.
The threshold on flourocarbon is higher than most, but even there, you hit a ceiling. Notice that the companies who offer these strings all stop at around the same diameter. It's not that flourocarbon isn't made even thicker than that - just that no one would ever consider using it.
That only deals with the issue of sound. The other problem is that the string would have such a great diameter that it would become uncomfortable to play.
By winding metal around a treble material core, strings for lower pitches not only regained their clarity, but also became thinner again. At what point to switch from one to the other is the great debate. I have my preferences, but they depend on the instrument and the tuning.
Good wound strings last almost as long as treble material - the problem is that good wound strings are (much) more expensive than treble material, and many string companies go for the lowest price and forget about quality and durability ("
after all these are ukulele players - what do they know?").
If you really want to avoid wound strings, however, the moral of the story is: stay away from instruments or tunings that use notes too low to perform well with non-wound material. This will probably mean low 4th set-ups on the smaller instruments. Even on medium to large sizes, think of moving your tuning up a step if you have an underperforming low a note in your present set-up. Or in other words, don't try to force the square peg into the round hole.
And thanks everyone, for the kind words on our strings!