How did dinos hold their necks?

It used to be thought the great sauropod dinosaurs held their necks high as they waded through the swamps. Then we figured out they didn't live in the swamps. Then came the idea, as shown in the series Walking with Dinosaurs, that the long necks were held out level to the ground, or even slanting downwards, balancing those long tails. Dr. Darren Naish, who never has a problem challenging paleontological orthodoxy, argues that no animal has ever evolved a long neck for low-level browsing only. Living animals like giraffes and saddle-backed giant tortoises use long necks to enable them to look around for food and enemies and to browse high vegetation. So, he and his colleagues argue, did sauropods.