Most of those changes get masked behind loops that I don't think either is very different for understanding.

I think the plusses outweigh the edge cases.

Having taught a couple beginners, I can tell you that what you see when you print a variable is very important. So, I guess it depends how these objects convert to strs, but I was assuming it would show a zip or map object rather than the result.

what are the edge cases? what are the advantages of iterators? less memoryuse?

Iterators get some of the benefits of lazy evaluation.