I'm betting he uses Data::Dumper instead of 'x' for the same reason I do: inertia. I've become so used to Dumper output that I can just glance at it and see what's going on. The output from 'x' is always a mental speedbump for me. I'm not saying it's bad, it's just not what I'm used to and I don't use the debugger often enough for this to be an issue.