Gimp yes, Inkscape no, everyone I sit in front of Inkscape loves it and it made me overcome my feeling of "I'm a programmer, I can't do art" thanks to it's great interface and smooth learning curve.
The GIMP I use because I'm used to it, but I find the interface a little annoying.
Even if someone doesn't like Inkscape, the issue of Inkscape's interface is completely different from the issue of The Gimp's interface.