All things being equal, it's a bit of a toss-up, because both should give you very good photos.
There are so many variables involved, especially with any Agfa:
- Does it have plastic or leather bellows? The plastic bellows are notorious for developing pinholes.
- Has the camera been serviced?
- Does the front element focus smoothly or at all? Again, Agfa folders are notorious for using grease that through the years hardens into a cement.
- Is this a zone focus or a rangefinder?
I've found the mechanics, particularly the rigidity of the struts, to be very good with both cameras.
Zeiss Ikon cameras in general were made to a high standard in choice of materials, design and quality of construction. An Ikonta C is a fine camera, especially one with a Tessar.
For either camera, there also is the question of a coated lens vs. uncoated lens, whether the shutter has been serviced or is stuttering on slow speeds.
Consider the ergonomics. Some Ikontas have a left-handed shutter release on the camera body, while with others you use the release that is on the shutter housing.
The Agfa Records have a right-handed release, which is more convenient for right-handed photographers.
I've not had a problem with a left-handed release, but some people don't like it.
As I said, if both cameras are in clean, working condition, it might come down to price. And then I would probably go with the less-expensive camera.