One thing that's important to me for packable jackets is that it stuffs into the pocket, or at least something attached to the jacket. Because if it's an included sack, I'm either going to forget the sack, or worse, lose it.
Another thing that I've noticed is that the more seams on the jacket, the more compressible it'll be.
I got DH a Marmot synthetic fill when he needed one for a trip and I couldn't find a Patagonia price I was happy with. I think it was just under $100 on sale. It was warm and kept dry better than my Patagonia. Could be because it was new and never washed. But my biggest gripe is that it's extremely hard to get it to stuff into the pocket and zip up.
Ditto everything here, except I like the hood for when it rains. Like today!