Swapped out neon voltage reference tube

I came across this thread over on TAoS where someone (Marco) swapped out the 85A2 ref tube in the power supply of their Croft 25R.
So for $15 all in, I shipped over from Colomor an English Electric CV449. Just tried it now.
Very nice improvement, the most notable being added color and timbre with increase in space between instruments and deepening of the stage. And then I played a few of my reference tracks. Hmmm. Let me swap back in the Raytheon. Way better. Yes, the lovely timbre is not as woody and sweet. But everything is more. More dynamics, excitement, timing, focus and above all, neutrality. I'd go as far as to say the CV499 may not have been holding the voltage at the right value. I could have bought a few used records for the price of that experiment.