Koetsu Rosewod Sig. Platinum Vs Urushi Platinum

hi,
I've been reading some old posts about koetsu cartridges cos I've been given
a chance to purchase one but I can't decide between Rosewod Signature
Platinum and Urushi with platinum upgrade.
So can you please help me by writing something about sonic differences between these two.
Tnx

My sistem

Kuzma Stabi S/Strogi S
47 Labs Phonocube
2x25 W Gaincard
Konus audio Essence speakers

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