I have wondered too if I should consider broadforking. I did notice a bed that had sweet potatoes the previous year perform better than a neighboring bed. This made me wonder if I could get better results with my beds that are only in their second season (or if that was just a coincidence).
I am resisting adding yet another variable to control. As I observe my soil, it does not seem that compact and that the earth worms and vole/moles are creating some decent aeration of the soil (I know, voles/moles not a great thing to have in the garden, but they seem to have minimal to no damage so far).
For the American gardener/farmers (and other locations like Sweden where Richard Perkins does small scale farming with nodig principals), it does seem to be a common practice. Although, I have not seen any controlled trials (that I am aware of). Will be interesting to see if anyone has done extensive trials. I know Charles compares to dug beds, but I am not sure if that is broadforking or double digging the beds.