Sometimes it's the little things that count - really.
I have a favorite lens - a Canon 28-135 zoom - which I've used forever and simply love. It's an extraordinarily good copy and even though it's a zoom it produces images that would be good even from a prime.
But the one niggling little thing it has always done that I am not completely happy with is, to leave me with just a little bit of CA - color fringing. I guess I'm particularly sensitive to CA - I really don't like it.
Camera Raw versions up through 6.6 have done a passable job of eliminating it, though I would often have to tweak the results just slightly, and often I just couldn't achieve perfection across the entire image.
Now with the 6.7 beta the CA is gone. I mean ALL gone.
A long, long time ago, when I had first gotten a new Canon 10D, I took a decent snapshot of a little car with this lens, and over time I've reprocessed the raw file over and over again as a fun exercise. I just did it once again using Camera Raw 6.7 RC1, and I just say, the absence of CA just struck me.
I remember the discussions, wayyy back when shooting raw was coming into fashion, where people were saying that better and better raw converters would become available over time, and thinking, "how could they get that much better?" It's funny, now, to be on the other end of more than a decade looking back on that, and realizing that the prediction really has come true.
To the Camera Raw Engineers:
Thanks for coming through with the new CA correction algorithm. It is MUCH appreciated. You've perfected my favorite lens.
I bought a used but still expensive pro quality zoom a couple of years ago. Lens Profiles reduced the CA but far from eliminated it. Even manual tweaking couldn't get rid of the CA evenly across the image, and I usually compromised. I also have a cheap-ish telephoto zoom which is more symmetrically affected by CA, but I could never totally eliminate it. My wide-angle zoom always needed a moderate amount of correction too.
Since 6.7, CA is gone.
I can't overstate how cool this is. Not only are coloured fringes a thing of the past, but my images are automatically sharper now, because the colour channels are correctly aligned by default. No arsing about. When working on images now, I keep finding myself thinking I've forgotten to do something.