GIMP gets the work done. I've never had an issue I couldn't address with its tools, but it's clear the UI was crafted by coders. I'm glad for this approach.
I completely agree. Every few years I give GIMP a shot, and every time I give up because it's completely inscrutable. Adobe is evil, and Pixelmator lacks features, but at least you can figure out how to use them in short order.
But most of all, any comparison is going to be silly. Photoshop has lots of amazing features and in sure is better in a technical comparison to Gimp in many ways.
A lot of times the best tool for the job is the one that works great for you.