The only reason I can think of is if you care about special features. A lot of times, they are only on the regular BD. But if not, give them to your son. They might as well get some use and be appreciated.Question while I'm in this thread (let me know if this is not the right thread to ask this question) . . . I buy only 4K UHD (Atmos audio) Blu-ray movies for my collection. Most DVD's I've purchased come with a 2nd Blu-ray disk. I have a Samsung 4k DVD player. Do I even need to keep the regular Blu-ray disks? I'm thinking of giving each one of the Blu-rays to my son who does not have a 4k player. He plays Blu-rays through his Xbox or Playstation.