Break in time for Nordost Valhalla

I own a pair of Nordost Valhalla interconnects and after several days of break in, I'm noticing little or no difference in their sonic characteristics. The mid to top end is still brittle and edgy. Is it 50, 100, 300, how much time before the cables settle down. I've read and heard for several years the merits of Nordost. I want to experience it. Any owners of Vahalla wire, give me your feedback.