I guess I'll have to get my butt in gear and churn out that ZF 50/1.4 -- C/Y 50/1.4 comparison. Maybe I'll get a chance to do something today.
Here is an old image that I know was taken wide-open with the C/Y 50/1.4. I don't think the look is "TOTALLY" different. But then some of us are more prone to overstatement than others, or are just more sensitive to differences that are really pretty small. http://boncratious.info/Zeiss50-14_test2.jpg
i think the C/Y 1.4 (well, the 1.7 also) have a VERY nice look to them, with a very smooth background... the ZF just seems very "unruly" to me (to quote my good friend Steven).