Should i upgrade my Meridian 508.20 to 508.24?

System:Meridian 508.20 into an Audio Research LS-3 pre-amp via audioquest diamond interconnect;ditto on the interconnect into the Plinius 100 Mk III amplifier.The Plinius feeds Magnepan 1.6 speakers via bi-wired synergistic mk ii speaker cables.Lovan equipment stand.The plinius utilizes an NBS Master II powercable;the meridian utilizes a King power cable (which is a temporary fix,i intend to purchase a Purist Colussus II).All plugged into a Monster 2000 power strip.
I have not heard the meridian 508.24.I believe the upgrade price is approximately 600.OO.Thanks for your input,i am particularly interested in hearing from anyone who has upgraded. Any suggestions on a powercord for the meridian are also welcome.