Krell CAST cables...which to buy?

I want to buy new CAST cables for my all EVO system (202/402/505). I think I currently have the original type.....purchased just over 3 years ago....about 1/4" diameter?
I have read many different opinions regarding the various choices available and would like to hear the up to date buzz on what is best. Unfortunately I cannot audition any so I have to make a god faith call on this.
My feelings on the sound of my gear right now is that it lacks a certain sparkle eg...cymbals seem muted and not metallic enough. Pianos don't have that percussiveness that they really have. Sound stage seems recessed. Not that I am looking for anything too bright.
I've read some posts that suggest the Nordost MMF is to fast and thin?
Any insight would be most appreciated.
Aloha.....