I've noticed that the only difference in nav_msgs/Path and geometry_msgs/PoseArray is that the former uses geometry_msgs/PoseStamped instead of geometry_msgs/Pose for the array of poses.
I'd like to know, what is the purpose of the additional headers? Shouldn't they all contain the same data (timestamp and frame_id) ?
When should I publish my poses as Path, and when is it enough to provide a PoseArray ? (Does it only depend on the API of the potential subscriber that I am targeting?)