I’m… very frustrated with GIMP and its development team. I really badly need a good raster editor and GIMP is just not that editor. The GIMP team tends to discourage suggestions and volunteer work that does not originate from within their group, so I don’t have a lot of hope of that changing.
Photoshop on WINE can be made to work, but it’s a terribly bad solution for many reasons.
I certainly don’t want to recommend either of them the way I do other applications and OSes in my list. Even the ones I mention that have frustrations are things I’m still willing to use (and enjoy) on a daily basis.
LEX writes in another reply:
Dump Gimp. Krita is the way.
Krita is great. It’s not perfect, and doesn’t provide some functionality I personally need. However, the Krita team really does seem intent on improving it and making it a better application, and that shows in its development and featureset. In time, I hope to completely replace anything I have to go back to GIMP or PS for.
Inkscape simply eliminated any dependence I had on other vector editors like Visio or Illustrator. It’s amazingly good. I’m hoping that Krita gets to that same place in the future.