Having read Stereophile for over ten years it is important to take all this with a grain of salt.
The venerable J. Gordon Holt reviewed a Sony CD player for $2000 in which he stated that while the Mark Levinson $30K player outperformed it did not do it by $28K and the Sony was the better recommendation. Last review...
When I was heavily involved and trying to make sense I was in a position to easily test some of the equipment they were reviewing in my own home and started to get a handle on what each individual reviewer liked and disliked. One man to beware of is the infamous Sam Tellig. At the time, 1990-1992, the rest were reliable and provided good perspective.
So does it ever end?
Sure, when you are happy. It helps a bunch if you have a goal. My goal was artifact free audio reproduction and while there could be some improvement the level of improvement will not be night and day at this point since I covered all the big stuff already. I am very happy and have no real hankering to go test and play. I have not heard anything to steer me any other direction. Course that's what happens when you start using headphones as a reference... Tough to beat that clarity and tone but I did!
Immediate future for me? Find a 2 way speaker I like and buy 6 of 'em. Replace my power house amps with something more practical for what I am now doing or based on new speakers have none (self powered). Take my X3 preamp from mere experiment to well built product. Get the dual volume control thing figured out with dual mono volume controls (to be applied to a multichannel job in the future).
Distant future? Find one or build my own (again) multichannel preamp that works correctly. Set up a multichannel system. Get a bigger house

The next night and day difference would be a much larger room. Pretty much maximzed what you can do with an average size room.
Much of the audiophile world is designed to keep you basically ignorant so you can keep on thinking it can be better rather than teaching you what is correct so you know when to stop because you are finally there.
You could be on target now. Send your player in and the sonic signature may end up heavier and just about everybody thinks more bass must be a good thing... Course if your system is light on bass this might be a good combo, ARGH! Synergy strikes again!
More bass. Kinda like making TVs with blue grayscales... You can't resist!