OP
It’s probably your brain acclimating to the new sounds. Does it matter as long as you are content, although I suspect that the upgrade itch will soon bite again
Don't do anything!
A couple months ago I posted a question on the forums that I was looking for the next level of imaging from my system and was contemplating better speakers. As per usual there were many responses of varying degrees advice.
Since then I have done nothing to pursue this next level. The reason for my inaction - my system is breaking. What I mean by that is I had made a few upgrades to my system - which were new power cable for the amp, newer speaker cables and finally a cartridge that has about 150 hrs on it. All of these changes are moving from the break in stage into what they can do for better sound. So now my system is maturing and delivering on what I am looking for. So the moral of the story is - leave it alone, stop tweaking. Let your system evolve.
Thanks for the advice fellow music lovers!