FWIW, I came across this Caps review at Lampizator, and found it quite useful as a general guide:
CAPACITORS
In this short article there's a graph plotting results across six competing attributes. After looking at it I came out with the following conclusions (again, this is only based on the authors' biased perception, but better than nothing):
Jensen Copper are all about midrange, in which they really excel relative to all others, but at the cost of trading off everything else! At the other extreme,
VCap Copper seems to be all about details, high freq extension and soundstage with a tightly controlled bass, but at the cost of killing the midrange (worst in the group). Somewhere in the middle,
Jupiter Copper looks as a balanced compromise across all attributes ... Not excelling in any, but not missing anything either ... The
Duelund Copper misses in controlling a tight bass, does not extend much at higher freqs. and is not good at details, but excels in soundstage, bass depth and midrange.
If it wasn't for the midrange sacrifice of the VCap copper, I would get those, but given these results, I prefer the balanced approach of the Jupiter Copper. Someone may want to combine the extremes of VCap Copper and Jensen Copper and get the best of both worlds, if that is possible ...That would be the best overall!
So, it is Jupiter Copper for me.