Neither of those are any more powerful than a high end speed-light though - the Profoto holds 76Joules (or "Watt-seconds" ), and the Godox light is about the same. A Nikon SB900 holds about 70J, whereas a typical modern studio head will be 500-600J I know the Godox V1 has a straight flash tube, just like any other speedlight, and by the looks of the Profoto light's Fresnel lens, it also has a straight tube, but I can't see any confirmation of that. (The round Fresnel head for the AD200 *does* have a round tube in it btw ). Apart from a slightly more pleasing light pattern, a round head just takes up more room. There are plenty of magnetic doodads for both round and rectangular speedlights.