I would put Audio Horizons at top of my list in terms of improving sound. Seemed to get rid another layer of imperceptible noise (until that noise is gone) so cleaner and more natural.
Aftermarket Fuses
Can I set the ground rules up front?? I hope so. There are two camps. One who can hear different audible reproduction using aftermarket fuses. The second camp can not justify in theory, or can not hear a difference in fuses. Fine. I respect both camps. Can we hold this discussion to those who can hear an audible difference in fuses?? Can we? If so, what is your choice in aftermarket fuses and describe, please, what you hear.