Best tweak?
Replacing the stock PSU supplied with Rega RP6 with newer NEO PSU. The result was amazing.
Not bad for about £200. At the time, thought this was a really good value tweak (upgrade).
For what it’s worth - having conducted A/B listening with same on the Planar 6, concluded the NEO offered majority of the difference to the newer model.
(Comparison of Ania - RP6 & Planar 6 - Aria - Naim XS2)