Precision Fidelity C7/A: To modify or leave as is?

Hello:

We recently invested in a Precision Fidelity C7/A and I was thinking of upgrading some of the OEM capacitors. The original designer -- Bruce Moore -- apparently built the preamp. to sound as good as could be in stock configuration without having to modify anything, i.e. evincing the philosophy that an intelligent design should be simple and sound excellent as is.

Has anyone upgraded their Precision Fidelity with caps. such as V-Cap teflons or Auricaps and come away with dramatic differences in sonics, either for the better or worse?

Thank you.