Hi fjn04,
I used Switchcraft, MSaudio, Vampire C7X, Xhadow RCA-SM, Duelund Gold RCA connectors.
I don't like Vampire C7X - it imphases high frequencies and have overall bright tonal balance.
MSaudio has great high frequencies and high-mids, but has a gap between mid-frequencies and base.
Duelund Gold and Switchcraft sound well balanced. My first impression was, Switchcraft sounds more grainy and Duelund more smooth.
I just ordered Switchcrafts to double check it versus Duelund again.
Xhadow sound is very "audiophile". It is smooth, transparent with big sound-stage, open and airy high-frequencies and big base. But mid-range is not as good as Duelund has.
I prefer Duelund 16ga to 20ga cable for interconnects. It sounds more balanced and dynamic. But it has lack of air and high-frequency details.
I'm planing to use Duelund cables from Werner Jagusch crossover to Altec 604E like you suggest in the future. (I'm using Belden 9497 cables).
I changed HF filter capacitor in Werner Jagusch crossover to Duelund RS + Duelund Cu-Sn Bypass capacitors. It was the best upgrade I did in my system for years.
Regards,
Alex.