[unfocussed_mike]

> One thing that Affinity and PhotoLine can do that PS can't is make curves adjustments in the Lab color space without having to change the entire document from RGB to Lab.

Yeah, this is super-useful. Also the layer blend curves are amazingly useful, particularly combined with live filter layers. And it can do LUT inference (e.g. from HALD CLUT images). I use that all the time.

> To be fair to GIMP, I used PS back to when adjustment layers were not a thing.

So did I, but GIMP has existed for almost as long as adjustment layers in PS! And for all that time they've refused to prioritise something that IMO is transformative in photoshop; it's the basis of non-destructive editing.

[120photo]

I look into what it going on from time to time, they are in the process of moving from GTK v2 to v3. Apparently it is not a easy transition but when it is done (GIMP v3) implementing adjustment layers and other new features should not take as much effort. I am going off memory so don't quote this as fact.