The Black outlet will give you more space between instruments, better flow, and a more relaxed feel to the music but with better detail. The Tesla plex does not sound as "sophisticated"- it has a little less detail. I do like the Tesla plex. Since my systems are each on circuits that have five outlets , I have a combination of outlets on each circuit.
SR essentially took the sound of the Tesla plex and improved it without loosing the good qualities of the Tesla plex. The Black takes a week of current passing through it to break in.
It is worth the price to me and does have the 30 day return option.
I think it is worth the time and effort to audition a Black outlet in one's system.
David Pritchard