I've owned;
Karik II
Ikemi
CDX (later with CDPS)
Karik III / Numerik (both slimline smps models)
The Ikemi was better than the K2, but hadn't the 'drive' of the CDX/CDPS. The CDX is flawed though, sounding somewhat artificial compared to the more tuneful Ikemi. The K&N has the drive of the CDX and the tunefulness of the Ikemi, and then some. Someone here went from a CD555 to a K&N and never looked back.
I've heard the CD12 a few times. Probably the most analog sounding player I've heard, but a little too polite to do justice to some material. Linn's streamers leave me cold - kind of soulless to my ears.
Mr Tibbs