I have been using The Gimp for about ten years. During that time I've had a few chances to use Photoshop at places I have worked. However, I've not had a job that has mandated becoming a Photoshop expert and have found The Gimp to be an excellent tool.
Without a solid reason for having to know a specific program inside out, I feel that the only thing I'm lacking by not having Photoshop is a substantial dent in my wallet
Wulf
ps. Plenty of examples of what I have done with The Gimp are on my
Flickr account.