Q: Why would anyone drop a wad on limited imaging software when there is an incredible pro-level open-source imaging app like Gimp that does everything you could possibly imagine - all for FREE?
A: Not everyone is an artist willing to spend hours learning to use a pro-level program like Gimp.
For kids, beginners or dabblers who just want something easy & quick to retouch photos or diddle around with web images, Pixelmator is an OK app. It has a Windoze-looking all black interface that looks cool at first but causes eye-strain after awhile. It does a lot of flashy FX & doodly stuff like shapes, so if you're into putting flowers & hearts & stars all over your photos, Pixelmator is for you. However, it has had stability problems in the past & won't run on anything but Mavericks, which is still a problematic OS that your favorite software may no longer run on.
If you want something more advanced & reliable, there's Acorn, which is just as easy to use but geared more to serious imaging. Acorn has a more user-friendly Mac interface that may be less sexy, but is more functional & intuitive, with a large array of useful tools designed for efficient image editing. Plus, it uses Python plugins, giving it more professional options. And Acorn is rock-stable. I've tried them both, & Acorn has never crashed on me yet. Acorn is more spendy & it isn't perfect, but it's easy to use & does a lot.
But compared to Gimp, both of these are kids toys with basic, limited features & toolsets. Gimp used to be a Windoze app with a reputation for being unwieldy & hard to use, but the new version, GimpShop 2.8.2 for Macs, runs native on Macs & is much easier to learn & use. It has a clean, dark grey interface that is infinitely customizable & comes preloaded with tons of incredible filters, brushes & plugins, with hundreds more available free online. It even uses Photoshop plugins.
Anyone willing to spend an hour or two can master the basics, opening the door to the magical world of unlimited creativity. There is almost nothing you can't do with Gimp. Anything you can imagine you can create. And since it's open-source, it's all completely free. So even if you don't like it, you aren't out any $. It also comes with a great user guide & there are many tutorials online.
I almost bought Acorn a while back, but decided to invest some time rather than $ giving GimpShop a try. It seemed a bit daunting at first, but in no time I had the basics down, and since then I've learned how to do things I never dreamt I could do.
Gimp is challenging at first, but it is also fun & fascinating. I'm still learning, and the more I learn, the more fun & fascinating it becomes..