A Furutech RD2 or Acoustic Revive RD3 will definitely help with brighter older CDs if that is a problem in your system.
What of your CD's have good sonics?
I have been amazed at the number of CD's are so bad I can't bare to listen to them on my system. It seems like over half are difficult to listen to. Vinyl seems about the same. I have been buying some classic rock albums from a local used record store and am surprised at how many of them sound bad. Most of the jazz albums I buy are usually quite good. How is it with you guys?