I guess I am in the "nothing significant that only one can do" group.
Partial download vs. Online edits
Really two very different techniques to achieve the same end. So I think that should drop off the list of what either one can't do. They certainly cause people experienced in one system pain when moving from one system to the other, but they both get the job done in the hands of someone familiar with that system. And I'll go so far as to say niether system is well understood by a large segment of the users.
Addressing differences
I feel the same way, the approaches are different but they achieve the same ends. I can have a lot of control over the physical arrangement of tags in PLC memory in a ControlLogix if I choose to. Once again, if you are familiar with the system, you can make it do what you need.