I've never figured out what makes the few parental trees so special. Unlike some unique parental trees of Dan Cong, for Da Hong Pao, there is no evidence that the few parental trees were the only surviving individuals of their varietal (Qi Dan, I think) before the cloning technique. They are old and they are at a good location, which make them good. But there is no evidence that they are the only old ones at a good location. So I don't know what's so special about them. Those guys who paid $20k on the "original" Da Hong Pao tea never speak up and tell us how special it is
That some 4 left trees are reported to be Qi Dan, Qi Zhong and Bei Dou..
But unlike Puerh, Oolong's specialty doesn't come from soley genes, it comes from men. Some 2nd generation, 3rd generation DHP might not be different genetically speaking, but it can be different weatherly speaking, minerally speaking and most importanly techinically speaking
One of my Korean Puerh sellers I know of once said, Oolong must be the most 'CHINA tea' the locals could be proud of, because it requires the technique which is a proof of history and culture of tea in China.
Not to say, Mongolian hotpot in Muslim town is a real proof, historically speaking