Having owned the Powercell 3, my advice is stick with what you have rather than invest $600 more.
upgrading synergistic research powercell cable
I purchased a synergistic research powercell, mkIII last year and later synergistic changed the power cord from the precision cord to their new copper tungsten element model. I can upgrade with them to the new cord for $600. Has anyone been able to compare the two cords and whether it is worth the money and effort?