A round head is just a show-off - uncomfortable and stupid. Has pros: 1. Rechargeable battery! One is enough in a warm room for more than 1000 shots. Finger batteries are no longer needed, this is yesterday's century. 2. Ease of control, each channel is placed on a separate button (this is for controlling multiple flashes) Some cons: 1. Unreliability, out of 5 flashes 1-2 in the correct exposure (overexposure, underexposure), one word is lying shamelessly. 2. Periodic freezes, freezes after the third frame at half power, not because of a lack of power, but just like that. 3. Not convenient since there is no built-in diffuser and reflective visor as on conventional flashes.