1. All are well done and beautiful shots.
2. I always thought Ziess were higher quality lens but the Minolta's you used flat out killed them in this set of examples. Of course we don't have duplicate photos for each lens but I was shocked at the difference. Ordinarily I wouldn't jump to such of a conclusion. But I know you well enough that you strove to bring out the best in each shot and lens so I don't fear jumping to such a conclusion. However! The Zeiss did the best I have seen in capturing the subtle differences in the white petals of the fourth in the set.
3. I don't know if I'm the only one who experienced this or not but I found it hard to focus on the white flowers in the fourth one done with the Zeiss. I really had the feeling of an impending swirling movement set off by the overpowering background. Maybe it was because it was so busy a shot. Sorry but I must plead ignorance on why That was my impression. I can honestly say I have not ever experienced that before. It wasn't because I didn't like it. In fact I liked the white flower the best because of its simplicity and detail. Unless you have superb light control you don't usually capture that much detail in white objects.
So! What is your assessment in comparing the Zeiss to the Minoltas? You have the experience. I don't and never could afford a Zeiss lens back when I wanted some.