On XE5, we have revamped IDE Insight to be always visible and make it easier to use, on the following video I show how you can use it, and all the key strokes you can use to get the most out of it.
Now, the tool is available as a toolbar at the top, and you can focus it using the mouse, or using F6 or Ctrl + . (dot), and you can start typing right away. The tool will show a list of available actions that match with what you are looking for. You can move through that list using the cursors and execute the item you want by pressing enter.
If you want to clear the field, just press ESC once, if you press ESC again, the focus will return where it was before using the tool, so this is very handy if you are typing code and you don’t want to switch between your keyboard and mouse back and forth.