I started with the e-collar when he was almost two years old. I wouldnt train the co pup with an e-collar.

By the way i trained GSD for years but no doubt in my mind that the co is totally diffrent.

the normal training doesnt work for the co.

It can really frustrating for you if you are used to a dog that respond immediatly.

Also dont underestimate the power of the co, the power of a gsd is nothing by the power of a co.