Consider a block with one [required] property and several not required properties.
Creating a block from within a contentarea all the properties are available, while creating the same block from assets panel only the required property is displayed.
Why the different views?
How can I display all properties, [required] and not required, while creating a block from the assets pane.
Also, creating a block from the Content Area does not fire CreatingContentEvent.
I know that the content is not created before the required fields are displayed when creating from a Content Area while using the Asset Pane does.
But when you want to hook up to CreatingContent to do things with your Content Types it's annoying that the two steps that are very similar to the editor behaves differently.