Garbage, just a gimmick. When you need to DL HD videos you have to purchase the pro version because it says it need powerful server infrastructure to DL HD formats. Lol what powerful server infrastructure? For HD you download the video and audio stream separately then merge them and that is done on THE END USERS SIDE.
Gimick.

"Youtube switched to separate audio/video streaming technology for higher quality formats and no longer provides direct 1080p/mp3 streams. Converting these streams to downloadable formats for you needs powerful server infrastructure, therefore 1080p/mp3 downloading has been limited to PRO users."