I'm a fan of Black Cat / Stereovox, but since switching to AES, I've not used a regular SPDIF cable for a while. However, BNC is always going to be preferred to RCA. This supposes your equipment has BNCs, obviously! Otherwise, things can get very murky in SPDIF cable land, cause what you're really trying to do is find the best match of impedance between your source and receiving equipment, and this is a lot of what leads to subjective ranking of different cables that are all over the map.
FWIW, I preferred the old Stereovox HDXV to the Silverstar MK1, and I preferred a (no longer available) Analog Research Technology UByte 1 (5/6ft or so coax) to the HDXV. This cable was so long in order to minimize signal reflections in most applications. Sounded really good to me. In more recent times, I liked a Neotech NEVD-2001 with WBTs from takefiveaudio in Canada.
