This is a bit old, but I am responding any how. I have tried GIMP 2, yes. I have also tried Paint Shop Pro, Photoshop, and Paint.Net (another free graphics program.) In my honest opinion, while GIMP is fantastic, I found it far more complicated than necessary to make icons. I have Photoshop right now and still...my icon-making program of choice is Photoscape. It's free. Just Google it for a download link.