GIMP is free under GNU license. I don't think it's right to compare a freeware software to an expensive one ! Sure Photoshop is better but its cost sucks! I prefer freeware softwares whenever possible provided that these softwares do not contains trojans,viruses,spies etc.
GIMP is better than nothing. It is free, of course. Photoshop is always good, but the price is painful so it is not nice for the Adobe to sells its Photoshop for a very high price especially the company is trying to domain in order to get rid of other small software companies. That's why the Adobe Company is a white flagship - that won the most popular software in the world.
You don't realize about Paint Shop Pro X and check out this website.
CompUSA.com: Corel Paint Shop Pro X - PSPXENGPCCOMP - Software » Graphics » Photo Video
You can try Paint.NET. Of course, it's FREE and powerful program almost same as PhotoShop.. Like the dude said "This program ... has actually made me uninstall Photoshop." So, why not give it try?
Paint.NET
I always hate high priced softwares .