My experience of Zeiss lenses is mostly with an older generation, in Rolleiflex mount.
I certainly woudn't describe any of the ones I've had or used as "highly center-optimized".
I've also extensively used Nikkor primes of the AI/AIS generation (many of the better ones too) and can compare them directly to the Zeiss ones: In my experience the Zeiss lenses *are* often significantly (as in somehow visibly) better even using the usual parameters (sharpness across the field, distortion & vignetting). Exceptions being perhaps the 105 2.5 & the 180 ED.
That said, again IMHO, where the better Zeiss lenses shine (pun intended) is in their flare control, colour rendition and 3-d effect. In short, their general "look".
That may sound a bit esoteric, but simply is...
Just a question: it seems that many who are dissatisfied with the new Zeiss lenses aren't using them with film (which adds a whole can or worms of various interactions and so on), is that your case?