For me, as a personal choice, I don't like them. I've had a wound third on my Cordoba mini and it just completely changes the character.
When moving over from steel strings, you may feel it all a bit strange, and long for a familiar feel, but the nylon string has its own characters for you to explore. The softer sound is inherent to the nylon string (relative to steel), and the softer third plays a large role in that.
Adding a wound third will do two things: Brighten that string so that it will be out of character with the 2nd and 1st, and also it will deteriorate very quickly. The trebles of a nylon string can normally out-last two bass sets, but a wound third will deteriorate quicker than the 4th string and will need changing often. If you decide to change only that wound 3rd string, it will be even more out of character with the rest of the strings.
Personally, I recommend you continue to experiment with non-nylon-polymer strings, and I think you'll come across a third string that you like and eventually get used to a new sound. I could be wrong, but I think you will prefer it in the long run.
I would try:
- Aquila Rubino (nylgut polymer + metal powder) (ask for a set made from 07.2017 onwards)
- Knobloch CX actives (carbon polymer)
- Aquila Sugar (sugar polymer)