Increasing Speed of Command Line Extract/Export with Apex Data Loader

I had a strange problem when I tried to automate a routine, daily export that I was performing with the Apex Data Loader (version 20.0 and 21.0): Exporting through the GUI only took 5 seconds, but exporting through the command line took anywhere from 30 minutes to 1 hour.

After 4 weeks, Salesforce Premier Support finally delivered a solution to the case I logged: Set the sfdc.debugMessages value to false. I'm very glad that Premier Support was able to find a simple solution to this problem.

Apparently, debug messages were so verbose for every record being exported that operation time increased by a ridiculous factor. Luckily for me, debug messages are not that important for an export.