Try and listen to your two cd players through a line level headphone amplifier (they;re not the greatest of quality mind you but most higher end dealers who are BIG and sell a lot of headphones probably have one. Commercial Electronics in Vancouver does because they also sell to professional recording studios. SO you can hook up a very good headphone from say Sennheiser, Beyer, Grado, Stax electrostats etc and then run 1 -8 cd players each with their own volume control all feeding the headphone -- thsi way you can adjust the volume level of each cd player so they are matched.

Place the same cd in each cd player and go to it. If you can't hear a difference with really good headphones then chances are you won't every hear them with loudspeakers and don;t waste the money. Therein also lies a problem -- even if you hear a difference with the headphones it still does not mean you will with a regular stereo amplifier and speakers. Some pricey cd players are deliberately made to sound different -- this is easy to do and if a DBT does not ever pick up cd player differences then you have to wonder about the test itself. CD player makers WANT to make their cd players sound different or better and that is the crux. Being different and being better are not the same thing. The mistake is to hear the $30.00 SOnic Impact and assume that the $1k MF is better because it is expensive -- and yes there is a huge "difference" in sound but I walked away thinking -- well the SI actually sounded good the MF sounded like a stereile boring lifeless mess.

On the other hand you may listen to a Rotel and much prefer it to the SI. You can;t base everything on a few experiments with a few pieces of gear.