I have been using Adobe Photoshop from the last 4+
years, I found it very useful & easy to use. I started
using GIMP only a year or so ago. I can not compare it
completely with Photoshop, but from the day I switched
to Linux I have to use GIMP, I am able to do almost
eveything I was previously doing with Adobe Photoshop.
So it means if anyone starts using GIMP (instead of
Photoshop) they will be able to achieve the same
result as one could with Photoshop. By doing so any
person or institute will obviously save hundred of $$
in licenses.