Southern by choice
Herd Master
With the electric one you would need to be close to an electrical outlet- the hand held one could go out into the field with you as needed.
I think the electric is intended for larger dairy herds. That's the impression I got. Buck Wheeler is the inventor and owner, I talked with him the other day. He is great at explaining everything about both products. I also watched all the videos.
I would get the electric if I had 1 cow to milk.