I'm originally a classical guitarist, so after an ErnieBall flatwound disaster, I wanted strings that felt smooth and didn't ruin my fingernails in 2-3 takes of a song.
I also love the feel of Ukulele Bass strings, that's why I looked for nylon ones.
So, they do feel smooth and to my surprise, after a month of playing they still don't show signs of wear from my fingernails, so cudos to Rotosound!
The sound does remind me of electric upright basses, great bass and the higher treble is there if you use single coils, but there seems to be a lack of mids and mid definition (but the bass is an active Ibanez, so it doesn't help).
All in all, they are extremely comfortable strings to play, with great intonation, decent sustain and very promising life expectancy!