I was a GIMP/Inkscape user first. I have access to the full Creative Cloud Suite but I usually reach for GIMP or Inkscape first because (for me) they are simpler.
I think one area where GIMP/Inkscape are far better is in the export options. Photoshop & Illustrator barely give you any options for jpeg compression or PNG output. GIMP's JPEG export lets me control color subsampling, optimization, and more. Photoshop just gives me 0% - 100% quality.