Gimp (and Photoshop) have a much higher learning curve. Takes a while
to understand all of their capabilities and how to use them. I don't
use (or understand) a fraction of what Gimp can do.
I use Paint Shop and I have V3, V4 & V7.
They are all different enough that I keep all 3. V7 is very good and
has features I have not even tried yet.
Forgot about that one. I used Paint Shop Pro for quite a while as well
but it was many years ago. Also a fully equipped image editor.