I do light graphics work too. Making blog post images and Youtube thumbnails mostly.
I started using Gimp a few months ago after 10+ years of using Photoshop. My biggest complaint is the quality of scaling an image down. It's really really bad compared to Photoshop (even if you play with the low level details of picking the scale strategy). It always seems to come out blurry or fuzzy, to the point where I stopped using Gimp for that. Is there a better way to scale images?
Also, I just wanted to throw in a comment of, if you're switching to Gimp, don't immediately discount it for not having features you're used to with Photoshop.
For example, with Photoshop, if you copy an image to your clipboard outside of Photoshop, then you when you create a new image in Photoshop, the dimensions of the canvas will be set to the image in the clipboard. This way it's super easy to make a new image, paste the image from your clipboard and now you have a properly sized image.
Gimp has this feature but it's not implemented in a way that's the same as Photoshop. Instead, with Gimp you can just press CTRL + Shift + V to paste the image from the clipboard into a new image and it's all set up and good to go. The menu item is "paste as... new image".