Depends on what you are looking for. If you want to see if you are turning enough, have enough weight forward, or have a steady head then it is probably a good idea to be able to view impact. If you are looking at clubhead movement in the swing, maybe not as important.
I have read many of the threads regarding filming and speed necessary and realize that a high speed camera is necessary to see what is occurring at impact. My question is, how important is seeing impact? Realizing this is very subjective. Many have stated that cameras or smart phone filming at even 60 fps are sufficient to observing angles, path, drawing lines and squares using appropriate software, lacking only the ability to slow the speed down enough so there is no blur.
Probably a tough question to answer. I am just trying to decide on an all around solution for getting the right cell phone and do not wish to spend the money for both that and a high speed camera that would only be used for specific purposes. I have mentioned in other threads about the Motorola G4 which has only a 30fps video capability at normal speed, but does have adjustable shutter speeds and can provide 120 fps at slow motion speed. I mention it again, as the price is right and the Moto has many of the same features of the higher priced Galaxy.