I balanced the player outputs by connecting the Sony with it's variable-level output and matched levels, both at 1kHz and with White Noise using my Sound & Vision Test CD and a Radio Shack sound level meter placed at my listening position. I had to make sure my "body shadow" didn't affect the microphone readings.
I have also given the other units a break by lowering the Sony a db or so below their levels. I still get the same impression with the Sony.
Last year I tried a Denon unit (Burr-Brown DACs) and found it's sound even warmer than the Sony's, but it seemed to lose detail in the process.
I still believe the output sections of the players contribute to this, and yes, I have read all the reports I could find on double-blind listening trials conducted by several magazines comparing both CD players and Amplifiers. They do conclude that under those conditions the statistical results indicated an inability to differentiate between units. There was even one where very high end equipment was compared against a system with a Sanyo portable player attached to an old receiver and using the cheapest wires and cables of uneven length, with the same result.
However I find with any system I have owned, I can prefer a different setup one month than I do another, and some of it seems mood-dependent and possibly even weather-dependent.
So I've tried reinstating my previous players from time to time, but I keep coming back to the Sony, no matter what output level I choose. (Strange for a person who has always preferred Philips units since "day one".)
The players currently IN my system are the JVC XL-MC222, Technics SL-DP9, and Sony CDP-950. The JVC is used for CD storage only (I've never really liked it's "sound"), the Technics for continuous background music, and the Sony for serious listening.
Also, Grammophone magazine, which I think is a more moderate periodical, has even commented that the reviewer first felt a newer CD player was better, then changed his mind after more listening (the units were both Sony esD models, with different DACs), preferring the older unit.
For me personally, I just feel more comfortable listening to equipment that I "feel" has a better presentation, even if "it's all in my head" ;-)
Music is such a subjective thing...