lol never noticed that backlight thing. I have had this unit for like solid 5 years.I have a set in the closet I'd happily give you if you were near me. The Z5500 may be ok for gaming, but they are deplorable for music because of the fixed, non-adjustable 125hz crossover Logitech used. Horrible design decision.
Oh, and they have the infamous Control Panel backlight issue that Logitech never would admit to or fix.
you may be right the reason I didnt get these was because I heard my friends system and it was distorting like crazy at high volume and it really turned me off from these. May be his system was just shit.