The east german zeiss lenses are every bit as sharp as the west german zeiss, regardless of what some people might say. The optics are comparable, but the fit and finish of the west german lenses seem to be a bit better.

One of the things that keeps me shooting the Pentacon Six tl are the marvellous zeiss lenses that can be purchased for about 1/5 the cost of comparable hassy zeiss lenses.

Mr. Monaghan's medium format site has some interesting comparisons regarding the east-west zeiss lens issue.