GT is my primary instruction and I'm folowing the Core Learning System but my practice sessions cover more than whatever GT lesson I'm currently doing. Likewise, my learning sources are more than GT -- I find help and instruction from other sources and the above mentioned Justin Guitar is my favorite 'other' online source. When I'm trying to get a better understanding of a subject, e.g., guitar theory, CAGED system, etc., I rely on YouTube, books, GT tutorials outside the Core Learning track, and even iTunes podcasts. Google search has turned up even more when I've been been pursuing a particular subject.

This doesn't demean GT...these are supplemental info sources just like school courses that use more than one textbook or outside readings.

If ya' need help or info, find it where you can but it'd probably be best to folow only one or two 'courses' at a time. IMO.

john