I don't know the answer either, so I'm no help.
I use Gimp at home, since I've got PS here at the office. I like GIMP because it is pretty full featured, but the learning curve is very, very steep, especially when compared to PhotoShop.
One other thing I /don't/ like about the gimp, the file sizes. The same size image made in both PS and GIMP, the gimp file will be up to 10 times larger using the same settings.
GIMP has been around a while, and they are improving, I remember the older versions, ouch.

So, they'll get better. There is a whole support-forum somewhere dealing with GIMP and how to get it to act like PhotoShop, but I'm at a loss now as I can't find my bookmark.
