4x4 lamping puts tackle in front of the dog's and that's about it. if done right there should be no injuries to the dogs unless they are freak accidents. Most who tend to knock it have never tried it in my experience.
It'd be a very wise move to make sure you vet the person who ends up with this dog...just saying like coz he'll be a peddlers/breeders wet dream. i'd have been interested meself but would get slated by certain members for taking the dog on.