It depends.
If you have a good enough TV (OLED highly recommended). If your a big fan of HP then it's probably worth it. I personally watched them on my 65" LG C9 and at times it felt as if I was looking through the camera lens. If you have a TV of this calibre you must use disc for the best presentation.
I did not keep this in my collection, but I enjoyed watching them. 4K really breathes new life into movies I've enjoyed in the past.