In an already bright system, the SMSG cables may not fit, but only because they preserve so much detail. They are incredibly neutral and certainly don't sugar coat the music - but I've long since learned the futility of trying to cure bad recordings with system changes. Better to approach high fidelity with one's system as best one can, and experience the recordings for what they are.
Hope this helps those considering Dave's cables. I now have a full set of D4 and SMSG cables in my system. They are world class.
I've had the D4s and SMSGs in my system for almost a year and, next to my phono preamp, they are the #1 game-changer upgrade I have made. So good, they blew the roof off of my cable budget in a very big way! But they were that good. I couldn't justify shorting my system by not using them after I experienced what they can do.
With speaker cables, I demo'd Shunyata at the same price point and the ZenWave SL cables easily matched those at a fraction of the price. I also owned a pair of Blue Jeans and those were part of the demo A/B process. The SMSGs are "next level" and for those of us that want neutral, exacting music reproduction, the SMSG is essential. As John said, trying to alter your system in order to "fix" bad recordings or bad mastering by coloring the sound is a deep, dark spiral of a rabbit hole. My system is 100% exclusive to vinyl playback and I have worked to put together a very revealing system. The ZenWave SMSGs are crucial to reproducing those long cymbal and reverb trails especially. That level of detail will make an audiophile release of a classic title like "Kind Of Blue" sound like you are in the studio with Miles & Co. You get all of those fine little details like Miles' quiet breath inhales, his horn sputtering at the end of his breath and in a way that is creepily present. In demoing the complete line of ZenWave SCs, I will say connecting any of Dave's speaker cables is like pulling a wet blanket off your speakers when compared to other SCs on the market. And as I have attested, A/B-ing anything next to the SMSG will quickly prove echo decay, reverb, cymbal trails all are extended much longer. The finest detail of the recording does not get lost in the transmission.
As for the interconnects, I demo'd an assortment from Shunyata, AudioQuest and Blue Jeans. I do not recall the exact models, but the AQs were mid-range on their pricing scale and the Shunyata ICs were at similar price as the D4. The BJs were cheap in comparison to all of these and a real contender with AQ and Shunyata. In fact I liked the BJs better than AQ. I found the BJ and Shunyata to have no major discernible difference. The D4s were obvious between the two. Like the SMSG speaker cables, they do not color the sound. That means you get all those fine details that make the music so much more realistic and sounding like you are in the studio. For me, the SMSG was a massive massive day/night comparison. When demoing, I did a lot of cable swaps. I ran each IC with each SC and took notes. It was a 4-6 week process. Much of that time was trying to convince myself the D4s and SMSGs weren't as good as I was hearing. But, finally, I succumbed and bought both.