I've long felt no need for a power conditioner. When we moved to our current house, back in 1995, on the advice of a fellow audiophile I had an electrician install hospital-grade outlets, wired to a discrete 20-amp circuit for all my audio gear. It was the most cost-effective improvement to my system that I've ever made, and I would advise anyone to take this step before doing anything else to treat your AC power.
Over the years, I've tried a few devices to cleanse the dirt that ConEd was zapping…