Sal is more of a fun guitarist and like any utube instructional videos, will not appeal or interest everyone. Sal isn't a dedicated flamenco guitarist and only dabbles with a few flamenco palos, however he does add some interesting ideas on technique.
Adam del Monte is definably a great guy and a talented knowledgeable flamenco guitarist, but as said above, he is very modern and commercial. I would not recommend him for learning and understanding old school flamenco. He no doubt knows it, but it isn't his interest and that reflects he his teaching.
Jason McGuire is mainly modern flamenco in his performances and teaching, but does have a solid understanding of traditional flamenco and a talented teacher. One would not go wrong with his instruction.
Jose Tanaka offers the best in internet instruction for old school flamenco in my opinion. He is the only one I know that offers only traditional if one request it. You don't have to wade through material that has no interest to you.
http://www.josetanaka.com/ Most of his material is modern, but his desire to please the student wanting only traditional, is commendable. here is an example of an old school Bulerias.
http://www.youtube.com/user/josetanaka# ... gCGRTcJ_8ANormans site is the best and has been for years. it is full of information and great examples of old school falsetas. it has been mentioned several times on this forum and well worth anyone bookmarking for reference.