Advantage to using a G-Code editor?

What are the advantages to using a G-Code editor like CIMCO for example? Text is color coded, you can backplot and edit the code (which you can do in a .txt file anyway). When using a CAD/CAM software, is paying for a license for a G-Code editor going to turn out to be useful at all?

I'm not all that familiar with G-Code editors, are they more useful than what I'm seeing?