Dmurfet, your specific issues / concerns could be one or a combination of problems. Still I find your response about line conditoners interesting but not surprising.
My initial response is, what is your experience with AC line conditioning?
You are correct in that some very expensive and beautiful systems have no regard whatsoever for line conditioning. And I'll also bet dollars to doughnuts their systems are experiencing much the same deficiencies you note above.
That's because AC noise is very real and universal and we all have it to one bad degree or another. Furthermore, digital noise is also very real. All this noise left untreated will leave virtually every system sounding fatiguing to one degree or another.
You may have noticed in my first post that I used the term 'proper' line-conditioning, thereby implying that there exists 'improper' line conditioners which are very abundant in the marketplace and often carry very popular name brands.
Sub-standard line conditioners are also very real. There are those that rob amplifiers of necessary current and thereby strip away all dynamics from the music rending it rather lifeless. There are those that do absolutely nothing. And then there are those that, even though they may clean something, they induce their own sonic harm and thus make the sonics worse than without any line conditioners.
With regard to the owners of these otherwise desirable systems, there are those who have never had an encounter with any, much less, proper line conditioning.
There are those who have tried line conditioning but since they've only tried inferior models, they walk away saying or thinking all line conditioning must be bad because I just spent $500 - $5000 on these units and they made my $200,000 system sound the same or worse but not better.
There are those whose systems need so much help that it really doesn't matter what they do.
There's alway those who simply cannot hear any difference no matter what they do.
There are those who own one or more components where the manufacturer (say a cd player mfger) has made their own attempt to address AC Filtering within the component itself. It's usually a half-assed attempt and sometimes with a $5 AC filter that may simply suppress certain offending frequencies. Some of the owners of this type of equipment audition line conditioners (good or bad) and almost always when one doubles up on line conditioning (especially when each employs different filtering methodologies) the end result is almost always disastrous.
So again they walk away saying or thinking all line conditioners must be bad or of no value.
And finally, there are those have acquired performance-oriented line conditioners and fully realize the significant gains that proper line conditioning provides. So much so that rarely is there a system worth listening to that does not have proper line conditioning as part of their system, regardless of the price of the system.
Given the above (assuming it's true), is it any wonder that an enthusiast or reviewer wrote that line conditioning may not be a good thing? Given the sub-standard performance of some line conditioners, the author is correct. But in the end that author is no different that one of the siutations I described above.
I can pretty much assure you this: If you did install 'proper' line conditioning in your system, (and barring any other potentially serious deficiency you may have) your system's sonic performance and ultimately your listening pleasure will meet or exceed almost every one of those very expensive and beautiful systems that use inferior or no line conditiong.
At least your equipment is certainly capable.
-IMO