There are a number of videos out there comparing these two drones. In this one:
SKSVideoGuy makes an interesting point about the obstacle avoidance proximity sensors. The P4P has sensors all around while the H+ only has forward facing sensors, and in the case of the RealSense versions, downward sensors. While that may seem like a disadvantage, he points out that since the P4P camera can only face forward, to get slider and backward facing shots, the whole drone must turn and fly that way. Whereas the H+, with it's 360-deg camera and retractable landing gear, can get all these shots while flying forward. Hence, only forward facing sensors are required.