It appears that Promo Only has both 360p and 720p videos. iDJPool only has 360p (and honestly, 360p on a projector or large tv is not very clear, standard television is 480, right?)
DVD is 480i or 480p depending on whether it's progressive scanning. 360p is probably close to standard TV. 720p is what most high-def channels do, though many are converting to 1080i (maybe 40% now).
I assumed the videos would be 480p to 720p, but they are all 360p. Many of them 'look' like they were converted to 360pm from 280 or something. I am happy with the quality of the mp3s, but the mp4s are lacking. It gave me a quick backlog of 2500 videos, but I will need to update them to 720p from somewhere really quickly. The website does say "We Have The Highest Quality MP3 320K" but nowhere does it say "High Quality MP4s" so I should not have just assumed.
Sadly, if someone sends me a link to a youtube video that is 280 or 360, I don't bother watch it. I always wonder what the point is watching such a low quality video. It's like listening to a song that is 64kbps. :/