I've done many tests and so far, I haven't found a difference between the two blocks, < = > and <is  identical to ?>, so, what's the difference?
Here's an example that reports differently for
These are not the same list, but they're equivalent.
In other words,
< is [ ] identical to [ ] ? > reports true if the two entities are the same object, not just if they are equivalent.
... Following up on that:
The reason it matters is that if two equal list values are identical, then changing one of them (with INSERT, ADD, DELETE, or REPLACE) changes the other, too; if not, not.
never tried that before, thanks