Duelund cast Pio Hybrid Copper/Silver or Rs series with Silver Bypass PIO

Zipost, 
I'd say that if you are committed to this region of top tier capacitors then get the CAST copper rather than the tinned copper version.  As Grannyring wrote,  these are the ones we've both have used with exceptional results. 
Charles 

Hi Zipost,
As I wrote above the Duelund CAST are excellent choices. I also have the Jupiter copper foil capacitors in my Coincident 300b SET amplifier that replaced the Solen capacitors for input coupling . Just as Grannyring wrote, these are excellent as well. The truth is that you simply cannot go wrong with either.

I’m very happy with both. If forced to choose only one I’d give a "slight " edge to the Duelund CAST (such a beautiful and natural midrange and yet without any weaknesses across the audio spectrum). Grannyring would I suspect give that slight edge to the Jupiter 😊. Summary,  you'll be very pleased with either is my belief. 
Charles

Zipost, 
I use the Duelund CAST copper capacitors in my Coincident speakers at the tweeter crossover and as output capacitors in my Yamamoto YDA DAC with superb results. I'm thoroughly satisfied with these upgrades. 

From what I have read from those who have done actual listening comparisons the addition of silver seems to improve performance even further yet.  I personally have no direct comparison experience but I don't doubt the impressions of those who do. 
Charles