I've owned Van Den Hul all-carbon and hyrbids (The First and D-102 Mk III respectively).
The midrange with the all-carbon First cable to me was some of the most neutral I've EVER heard. With both tube and solid state, it just showed what the equipment in front of it was doing. A lot of folks who love the SET sound have used these (I sold one of my pairs to a very nice gent in Hawaii who had all tubes and loved these).
For me, though, the roll-offs in the frequency extremes (I assume due to capacitance, maybe other) was too much negative to offset that glorious midrange.
The D-102 Mk III Hybrids ALMOST mated the best of both worlds. It balanced out things a bit more, but I found the mids a little forward and colored, and the highs not as natural sounding as I'd like. Maybe it was a glare in the upper mids/lower treble, not sure; it's been a while since I listened to them in a good system, though I still have them.
Michael Wolff cables have consistently received good to great reviews, and he uses carbon quite a bit. I think his latest, which mix carbon with metals (Gold/Silver IIRC) have been recognized as his best ever.
I used to own a Wolff Carbon Source power cord, it was very nice; black background, no noise, tight bass, and perhaps some positive effects into the mids, can't recall.
Capacitance in Power Cords seems to be more a positive than IC's; TG Audio also had some higher capacitance PC's I believe, and I always loved their sound.
This is some of my direct experience, as well as what I've read here and elsewhere. Hope it helps.....