As someone who uses Photoshop almost every day, it's nowhere near a "photoshop killer". The workflow is still one of the worst I have stumbled across.
But it works, because you know it really well and have spent (literally, in most cases) years perfecting your art. You haven't done that wiht GIMP, so of course it sucks. But the suckage isn't inherent, it's because the problem is inherently sucky, and you've simply trained your eyes not to see it.
For the record, The GIMP doesn't even have what we call "Non-Destructive editing" which allows to make a change to some of the filters and transformations you did on the image much later even when the image has been touched by other editions. It has been supported by Photoshop for way more than a decade, already. After all of this time, the Gimp still works like a toy and has zero productivity.
Zero. There is nothing productive about The GIMP. Anything you can do in The GIMP will be done faster with a competitor, Photoshop being the best in the category.
And before anyone comes to tell me that "THE GIMP IS FREE!!!11!ELEVEN!", Photoshop isn't expensive for a Photographer either, so price does not enter the game here. If you're a photographer with one or more DSLR bodies, lots of lenses, travel equipment and so on, spending some money on one measly Photoshop license is not going to kill you. The gain in productivity will more than make up for the money spent anyway, the Gimp truly is an awful tool compared to Photoshop. If you can't afford something like Photoshop it means that you can't afford being in that business in the first place.
I've tried Gimp numerous times, and the lack of smart objects/filters makes it a complete non starter. Generally I found I could do most of the things I wanted to in Gimp, but they required many, many more steps.
Also, I've used Gimp a bunch and I've read the Gimp book from Apress and as far as I can tell there really is no such thing in Gimp as the non-destructive editing Nicole060 describes (assuming I understood the description correctly--that you can say first apply levels, then sharpen the image with unsharp mask, then go back and adjust the levels some more without the need to re-apply the unsharp mask--I don't think you can do this in Gimp.) So it's really a shame that the comment you replied to, which is truthful and presents a valid point of view, got downvoted into gray. And I'm saying this as a fan of Gimp who never used Photoshop.
edit: found US price is $699 (before tax, Aus is post-tax). That's still not 'measly' in any context other than professional.
Of course, this essentially puts one more barrier for people who can't afford formal studies. And especially with the DRM becoming more and more effective, I've actually seen this being a significant obstacle for designers-in-spe from e.g. Poland (where even the discounted price is quite a lot of money). They deal with it, one way or another, but it's always a huge strain.
As for the established professionals for whom the price isn't terrible -- well, good for you, pat yourself on the back for being rich. Less competition that way, or something.
[1] But see this gimp document - the first returned hit in a search for [gimp drop shadow text] - which appears to be weirdly complex.
http://paintbrush.sourceforge.net/
...what?
And yet photoshop is heavily pirated software.
By pushing other softwares, such as gimp, I'm not in anyway saying that photoshop is bad, or that gimp is a photoshop clone, or that the people who need to use photoshop should switch to a free open source alternative. I'm just trying to get people to move to a more suitable tool, and to stop using pirated software.