A silent killer of user experience is audio desync. Low-quality pirate sites often suffer from a 0.5-second delay between movement and sound. The "high quality" promise ensures that audio codecs (AAC or MP4) are perfectly muxed with video tracks.
Click randomly to 25%, 50%, and 75% of the video timeline. On a low-quality site, this triggers a 5-10 second rebuffer. On a high-quality pass, seeking is instantaneous because the server uses Range Request headers to fetch only the necessary bytes.
Ask these four questions:
If yes to 3+ → high-quality entertainment.