Add my name to your list of those that find the Tabulus Argentus DB-25 cables a great upgrade. I bought a pair of the 2 meter cables for my Pass Labs XVR-1 3way active crossover (2 power supplies). The XO has been powered up continuously for 6 weeks, and I have maybe 75 hours of active listening. It may be a little early, but here are my impressions based on break-in period listening and auditory memory of what the unit sounded like before I installed the cables - admittedly a very haphazard approach. Despite extensive modifications made to the Pass Labs XO done some years ago, the new cables showed there was still room for improvement for the XO and my system.
The improvements? There is an increase in image density. Vocals and instruments acquired a more 3-D character and everything is a little more solid and present. Soundstage is more open and alive. On very well-recorded tracks, you can hear into everything in the space of the recording venue and almost feel the atmosphere of it - it is not black. The other change, more audible at the end of some tracks, is that the notes have really beautiful "hang time". They'll very slowly fade away at the end of the song for example. I do feel now that I'm hearing absolutely everything on the recording, including how it was recorded, good or bad. Some of the 60s rock recordings are a lot worse than I remembered. Early on, I heard more bass, but that's not the case now.
I guess there's a small reduction in noise to allow me to hear all this. My system has no obvious weaknesses I'm trying to improve, only ones I may discover after they're gone. At times, during the listening sessions on some of my best sounding CDs and LPs, these cable's sonic changes were very startling. Perhaps there's a little burn-in left, but the system has settled in quite a bit.
Especially considering the price, these cables were a high-value upgrade to my system. I can't image why anyone wouldn't buy these.