When to use Views attachments vs. content panes? Up until now, I've always used content panes provided by Views in Panels to accomplish tasks like "Related content" and "Additional information about ABC."  I just realized that Views also provides an attachment display, which as far as I can tell seems to be similar to a content pane except it doesn't require Panels.

However, if I'm already using Panels, are there any use cases where I would be better off using an attachment instead of a content pane, or are these basically the same thing?
Attachments can inherit the exposed filters of the display they are attached to.