The videos are embedded on the site, which essentially means they play directly from YouTube via a window on RSOTC.com. The video above plays fine for me although it starts out in 360p (a low, blurry resolution) but automatically adjusts to 720p (hi-def, very clear) after the first few seconds of playback.
How quick or even IF the video will automatically adjust to the 720p Hi-Def resolution depends primarily on your internet connection speed as well as your PC hardware & settings. Try manually selecting the 720p HD playback quality from the settings. If the video freezes & buffers before resuming, then it is most likely due to you internet speed. Let me know if the issue persists.