I can’t disagree with salectric’s point, it boils down to personal preferences and that will never change. I haven’t used the V Cap copper but have experience with their Teflon tin foil and OIMP capacitors. We all simply hear what we hear. I could see where someone would categorize the Teflon V Cap as more ideally neutral and a preferred choice depending on the particular component, system character and objectives.
Jupiter and Duelund CAST are beautifully "natural"/organic in character/tone and this is what I find most important and desirable. It depends on what a listener prioritizes, no right or wrong. There’s a capacitor available that will suit a given taste once one determines what specific sound they’re seeking. Plenty of good choices.
Charles