I find that GIMP is horrible with resizing photos and pages, unless you do the damn resolutions/coordinates check which is damn hard. Sometimes I like to use MSPaint just because it resizes in a snap. Pixel art is outdated though...
I will use GIMP for some spinny heads, but IMO it's horrible for me. I want to buy photoshop, but like Blam said it's really bloated, whereas GIMP and MS Paint are a lot... neater.