Who prefers box or underscore as a cursor option?

This morning I was configuring an app and it gave me three options for cursor styles: box, underscore and vertical bar.

The vertical bar has always made sense with me—it lives in-between letters, for example: when I see "test|ing" I know that my cursor is in-between the final "t," but before "i." If I type "X" I'll get: "testXing."

By contrast, in this app the box cursor is like this: "test[i]ng" and if I type "X," it's not obvious to me that I'll get "testXing" instead of "testiXng."

I get that this is a matter of preference, but I'm curious to know why underscore and box would be preferable to vertical bar.

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Here's images of the same cursor placement, but different styles:

- Example of vertical bar: https://user-images.githubusercontent.com/24446573/156610316-47df7923-744a-4b14-a23a-ddbac873ba59.png

- Example of underscore: https://user-images.githubusercontent.com/24446573/156610217-120f96f8-2f82-4577-8a02-67458d663841.png

- Example of box: https://user-images.githubusercontent.com/24446573/156609948-4f814ef6-9a30-4cfe-9db7-1ddbe75ec051.png