Nordost Shiva, Vishnu, Brahma?

I agree wholeheartedly with Episteme's comments. You will get more bass weight and better overall soundstage with the Vishnu. It is a huge step up from the Shiva, which is a great cord, but as you've pointed, a little lightweight. I use Vishnus on my Rega Jupiter 2000 CD player, and Quicksilver Horn Mono amps.

I've had all three: the Brahma is the most solid of the 3 with much more weight than the other two.

I did a Power cable shoot out and had the Aural Symphonics come out ahead. You can see further results on my system post.
Please remember its all about synergy in your own system.

i have been auditioning a variety of PCs for my esoteric, same audio as yours, but in a very different system, so my comments can be taken in general only and within the context of my system.
i auditioned the brahma and valhalla on my ux-3se. with a TA ref xl [latest version] PC on the preamp, i preferred the brahma over the valhalla as the val thinned out the highs greatly and introduced glare. my system is already quick and resolving. speed and clarity was great with the valhalla though. the brahma was a happy compromise. however, neither nordost in my system seems to be the best choice. recently tried shunyata helix alpha [non-vx] on the cdp. the python was good, the anaconda clearly better, but less weighty overall than the TA ref mm PC i auditioned. the shunyata gave a more balanced top to bottom presentation IMO in my system. the nordost gave the extremes a thin clarity, the Transparent clearly gave huge bottom end wt, perhaps more than i need in my system. i will audition a few other PCs before finalizing. i have heard that some PAD PCs may be an excellent choice for the x-03. there are a few different PAD choices, no one can really advise you which is best in your particular system. check out some threads on here. there are numerous PCs in $500 - $1000 - $1500 - $2000 plus full retail price ranges depending upon length. dont know if anything here is helpful. cheers.

I've auditioned all three and prefer the Brahma. I was expecting the Valhalla to be a significant improvement over the Brahma, but it didn't work out that way for me. The difference between a Vishnu and Brahma, even on a low power consumption digital source is very apparent.