I still don't get the utility of having a DVD and a BluRay in the same package.
It's like buying digital music, and have the bundle for a FLAC audio, a 320 bit MP3 and a 128 bit mp3. Which is even a bad example because an mp3 takes less space than a FLAC file, and you might, dunno, keep the FLAC for your computer or stereo while you put the mp3 on the mobile device, while if you have a Blu-Ray player you don't need to watch the same thing with lesser quality, and if you have just a DVD player a Blu-Ray is as good as a coaster.