Tubes for Pathos Classic One MKII

Hello,

Has anyone tried the Electro-Harmonix 6922 or the Electro-Harmonix 6922 Gold version tubes in their Pathos Classic One MKII Int. amp? How do they compare to the stock Sovtek 6922 tubes? I thought that the sound of my Pathos was actually quite good with the stock Sovtek 6922 tubes and I am not sure if its worth trying something else now that the tubes need replacement. Or, should I splurge on expensive tubes like the Mullard NOS or Amperex NOS tubes.

Thanks !