I've tried both.
I hated Chess King... I only used it once, as I remember. (A few months ago.)
As I recall, I couldn't configure the look of board the way I wanted it. Nor could I configure some of the screens and windows and background colors, to set them up the way I wanted.
Also, if I remember correctly, that GUI doesn't allow you to use other chess engines, which was the absolute deal-breaker for me. Once I realized I was stuck with one engine, I wasn't much interested any more.
Fritz 12 is more for power-users. I got the impession Chess King was more for "kids" or for your average chess player. So yes, I would say that generally, Fritz12 can do everything that Chess King can do, and probably a whole lot more.
Anyone tried both of these? Does Fritz 12 do everything that Chess King Houdini 2 does?
(Trying to improve my game) Does Chess King Houdini 2 do things to improve my game that Fritz 12 doesn't do? Thanks in advance for any help. Davy