The result is displayed in list view. Every list view in AmiBroker supports copy-paste and can be directly "exported" to Excel or Notepad or whatever else with 2 key strokes. Ctrl+A (select all), Ctrl+C (copy in AmiBroker) and Ctrl+V (paste in Excel)
Speed depends on number of data errors. If there are lots of errors there can be hundreds of millions of lines to be outputted in list view.
Update: apparently with lots of reported errors, most of the time was spent updating the list view. In 6.40 (in-development version) updates are minimized making the whole process a lot faster (10x or more).