I love the black myself, only done it once mind but I was really impressed, the boundary trail, goat track and deliverance are classic bits of trail. And nicely worn in too, so it’s not got that industrially built feeling of the red. Agreed that most of it isn’t very black but still, I love it, it’s more like an amazing local loop than a trail centre route to me.
(but admittedly, I did bottle the wormhole and one of the other sections as I’m hopeless at steps, I’ll give everything else a go but they put the wind right up me… I had to get off and walk the double step at innerleithen too)