I originally had this fully strung with Nylgut reds, but the 2nd string snapped, so I replaced the 1,2,3 and 5 strings with light gauge nylon, but kept the red 4th to avoid using a wound. I could barely tell any difference in tone or volume between the two types, but they do feel slightly different to play. I have used both reds and original Nylguts before, without any problems, but I think I'll just stick with nylons from now on.
BTW if anyone knows a supplier of real gut strings, please let me know :)
12" Cherry block rim
Rosewood tone ring
Calf skin head
25.5" scale Rosewood fingerboard
Light gauge nylon strings with Nylgut red 4th