The Zeiss lenses I was talking about are for Rolleiflex 35mm SLRs (several models built between c. 1970 and the 1990's). Often, but not always optically the same as the Yashica/Contax lenses...
Some of the new lenses are definitely different (a 35mm f/2.0 didn't exist and the 18mm has a different nominal aperture) and it seems to be debated whether others are exactly the same as their old versions.
That said, apart from the 15mm & 18mm, I have very different results regarding edge sharpness and distortion (15mm - Leica version, 18mm, 25mm, 35mm 1.4 & 2.8, 50mm 1.4 & 1.8, 85mm 1.4 & 2.8, 200mm).
The lack of aspheric elements seems to be part of Zeiss' design philosophy.
While Leica, for example, embraced aspherics and I admit that later Leica lenses are technically better than my Zeiss', I still like the overall "look" of the Zeiss' better.