Should I upgrade Purist Audio Design Proteus Rev B from fluid filled to Ferox?


Advice sought. My Purist Audio Design Proteus Rev B speaker cables are slowly losing their precious fluids (Dr. Strangelove joke). The company says they will upgrade to ferox for about $400 plus shipping charges They say almost everything will improve. Does anyone with experience with these cables have an opinion on whether ferox is better than fluid? My speakers are PSB Imagine T3s.

Thanks for your help.
brentj
All my cables are Purist with Ferox it is much better than fluid at $400.00 it is well worth it.Been using Purist for 25 years and love it great co as well.The cable will have less noise as well.
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Thanks EBM! They do seem like a very good company.