It's far, far better than perl's default (and clumsy) command-line debugger. perl -d is okay for trying things out, and experimenting with the language, but for debugging actual programs, you need ptkdb.
Also, this is the only debugger I know of that enables full-screen on-demand debugging of CGI programs. If you have an X server, and your webserver is apache/*nix, you can set it to pop up on your display when you visit a CGI program in your browser. OUTSTANDING.
A graphical debugger for Perl?! REAL programmer don't need that!
Well - I do!
The graphical interface is intuitive and easy to use. Makes it easy to debug - without having to remember dozens of flags.
Hope to see an editor included...