Harvey,
Sorry but I never go to this section of Audiogon unless I change a piece of equipment.
The Kleos is a much better "audiophile" cartridge, no doubt. It has better detail, sharper focus, etc. All the things that someone listing to High end audio equipment would appreciate.
But
I liked the music that the Zephyr made better. A really enjoyable cartridge for a person that wants to enjoy music.
Can you have both?
I understand that Soundsmith makes a more refined (read more $) cartridge that is worth researching.