I had been searching for a lightweight, packable puffy for an upcoming PCT trip and found this jacket, an absolute steal on sale for around $50. Roomy enough for a couple of layers underneath, but trim enough to wear under a rain or wind jacket. Not sure it would be warm enough for temps much below the high 20's, but should do the job for most 3-season trips.
This review was written in the old system and had content requirements that are different than reviews written today.