Down sleeping bags are popular among lightweight hikers and campers due to their superior warmth-to-packability ratio. Quality down provides excellent performance, longevity, compactness, and breathability, making it hard to match with any other material.
On the other hand, synthetic sleeping bags perform better in very wet conditions compared to down sleeping bags. They are a budget-friendly option and slightly heavier than down bags, but still a good choice for those who don't mind the added weight.