This is arguably the most critical feature. "Dual Audio" means the video container (usually MKV) holds at least two stereo or 5.1 surround audio tracks.

You might be skeptical. Can 720p do justice to the lush watercolor backgrounds of Studio Ghibli?

This is the magic number. Princess Mononoke runs for 134 minutes (2 hours and 14 minutes). A standard raw DVD rip is roughly 4.7GB. A Blu-ray rip can be 20GB+.