I have used Silver Anniversary XT then Chord Silverscreen which wasnt an improvement in detail but did give an overall better sound with better bass and less brittle treble.
Then i pushed the boat out and got some Chord Epic which were a very worthwhile upgrade despite the cost per metre. More detail, clearer bass and much better overall presentation.
I have had much less impact from various interconnects and didnt think any upgrades i tried above the £50 level of VDH Name / Chord Cobra 2 gave any real improvement at all in my system.