It's definitely not dark. Treble is less rolled off than the Audeze stock cable and there's even a bit of sparkle there. I'd say it's quite a bit less bright than the Silver Poison, but maybe a little closer to neutral. Everything feels quite smooth and easy on the ears, yet very detailed.
As for which of the two is better, that'll depend on the headphone and the music you listen to. For what it's worth, I could see someone who listens to rock music preferring the Silver Poison and it makes a good fit with darker headphones. The Virus seems to play straight down the line, neutral with slight emphasis on bass, imaging/presentation and microdetail, it will be the cable that will appeal to the most people in the most situations IMO.
Thanks. Im really excited to receive mine.