WBT connector upgrade

I�m about to order a 4m length of Kimber Hero interconnects with RCA connectors. The standard connector on the Hero is the WBT-0144, but you can upgrade to the WBT-0108 for about $70. Need some input as to whether the upgrade is worth the extra money. The interconnects will be used between an Audio Research SP-9 and Classic 60 driving Vandersteen 3A Signatures. Thanks!