Reelex (Reetz - Celex interface) note on "Nice or Fast output".

The search results can be displayed in a table that looks 'nice' in your browser, but that includes many (hidden) data which might make the output slow if your internet connection is not very fast. There is also a 'fast' option which separates the output data only with tabulators, which might not look so nice on the screen.
In case you want to cut-n-paste the output into a text file, the 'fast' option is actually better, since the tabulators are already in the right place to convert the data into a 'nice' table in your word processor, spreadsheet, or statistic program.