WebDirect is great - at last I can have custom dialogs to ask the user before taking action (e.g. Do you really want to delete this record?). But there are two minor differences between custom dialogs on Pro and WebDirect:
1) Display of long button names: On WebDirect in Safari the button name "Do No Delete" is shown in full, but on Pro "Do Not Delete" has the last letter or two cut off because of the width of the button.
2) The default button in Pro is, as any Mac user would expect, at the bottom right of the dialog with other buttons to the left; but in WebDirect the default button is to the left of the other buttons. A consistent order would be nicer.