I don't think it's a fur type, but I do agree that it seems harder to care for then the others. Flynn is a Chinchilla Holland Lop and her fur is WAY thicker then any of our other rabbits, she seems more at risk for matting in certain areas so I really need to watch her, particularily around her tail.
Their fur isn't nearly as thick as an actual chinchillas though. My chinchilla, Magyk, has probably some of the most beautiful fur I have ever seen on an animal, it's stunning.