@Ai: Man, with all those features that sounds like GIMP will be the ultimate pixel art tool. As long as it is not about animations at least. 
Oh, you read my other post that describes the full indexpainting support? Yeah, it's pretty damn handy. Didn't use it for this particular picture though, it was done in RGB mode / Normal blending mode @ 100% opacity.
WRT animation, I agree the default setup is not very helpful, but my experience is that GIMP-GAP is pretty good. For a small simple anim, GrafX2 is more comfortable, but for more complex things, the multi-layer-per-frame setup (and all the other things!) GIMP-GAP provides is more convenient (eg: scrolling BG / parallax, moving animating objects over a complex path.. ). Unfortunately GAP isn't available for 2.9 yet though.
We don't have HDR indexed images yet. I mean, that might sound stupid, but I suspect it is quite useful if you need to model changing light conditions.
Personally I have both 2.8 and 2.9 installed, which allows me the best of both worlds (2.8 has more plugins, especially GIMP-GAP and the remarkable GMIC, and is a little faster, 2.9 has HDR support, canvas rotation, recent colors palette, indexpainting and 'indexcompositing', and some other new tools). I can have them both up at the same time by launching whichever one I run second with the -n (new instance) commandline option.
Currently using GIMP in preference to GrafX2 because GrafX2 has a scary bug relating to save-as:
Supposing you load a.png, modify it, and save-as b.png. If b.png already exists before the save, a.png will be erased when you do the save.Overall though I wouldn't strongly recommend 2.9 yet. It has a lot of compelling features but more developer know-how is currently required to effectively operate it than 2.8 (or the eventual release 2.10 that 2.9 will become).
