gimp can't even begin to compare with Photoshop on a filter level, especially in areas like burn/dodge. I don't know how it applies it but Photoshops application of filters is much more intelligent. Not to mention Gimp has an absolutely baffling ui philosophy (paste as layer/yellow square/brushes not painting) while Kritas seems sane at least, mimicing popular photoshop features and even improving it in some cases.

In an ideal world, gimp is retired and Krita becomes the Photoshop alternative and the community can focus on really getting behind Krita.