I can't believe I never noticed this till today, but it seems Quicktime X hasn't been uploading to youtube properly. HD files uploaded via Quicktime X max out at 480p on youtube. Meanwhle uploading the same file via youtube.com uploads to 720p. Has this been a Quicktime X bug since day one, or is this something new?
I've now learned to make sure to double check my videos after uploading grrrrr.
I've now learned to make sure to double check my videos after uploading grrrrr.