Many users, many needs...
You can customize the layout of iGTD window controls. Depending on your needs, you can...
...hide columns you do not use
Use the button in the upper-right corner of the task table:
it pops up the menu:
please uncheck the columns you do not wish to be displayed.
...customize the iGTD toolbar
Default toolbar of iGTD can be customized easily. Please use the contextual menu of the toolbar:
It's the default toolbar menu of each Mac application.