The differences between the two have to do with how well you know the apps AND most importantly how much talent you have
Umm, no, the differences between the two have to do with the capabilities of the respective applications. Try creating a CMYK document with GIMP. Then realize that a professional graphic artist needs CMYK, not RGB. GIMP is not a professional tool by any stretch of the imagination.
That might be funny if you needed a crack for iPhoto 2, but actually it is a free download for anyone running Mac OS X v10.1.5 or later