As far as I know from other posts on the topic, all of the old "LD" vids are being reshot in HD. This, of course, takes time. One instructor, for example has something like 1,000 videos.

I was also member of another site that happened to have consistently high quality videos, however, I found GT was more what I was looking for, which was learning to play, rather than learning songs.

I am not familiar with JamPlay, so I cannot give you any opinions on that.

Also, if you have not noticed, there is an option on the player for high or low quality playback that might help.

Hope that helps a bit!