So today I used some of kens diamond films to sharpen a ZDP-189 Endura , for a customer. My progression went like this.
140 Atoma , 220 , 1k shapton , 15u , 9u , 3u , 1u , 0.5u HD Diamond Films , Stropped with CBN on Roo , 0.5u , 0.25u , 0.125u , 0.1u
At 12DPS its nice and sharp.
The HD Diamond Films are excellent , and I highly recommend them. I have some more coming so that I can replace the entire bottom half of the progression above with Diamond Films.