The big shocker? They are not bright (IMO)! They would show the shortcomings of gear and source material, warts and all.
I have tried to trip them up with all my "bright" test recordings...they don't stumble. I'm very sensitive to the hard and etched or glassy top. With my gear and ears they track whats available quite honestly.
From close mic'd Soprano or upper register Violin and to the last twink of Piano.....quite good indeed. The "peak" everyone refers to at takes place in the "air" octave. Not much fundamental use up there. No hole in the mid-bass either, that is one of the most natural areas....again with my gear and ears. You have to take headphones off and Gage the ears with Live Music...or above average speaker system and room. Most "budget" phones are very colored, many top-end offerings also, again (IMO).