Keepvid gives me the option of save as standard, or save in high MP4
Downloading this,
http://uk.youtube.com/watch?v=XbVtbc_XzrI&fmt=18
gives a 11k file as opposed to 7k in standard, its higher res........and better
Have a look round on
http://www.vimeo.com/ for much better quality,
try
http://www.vimeo.com/752979 or
http://www.vimeo.com/1090182