I took up guitar at age 63, took lessons for a few months from a couple of different teachers, and after 3 years was able to teach myself a bunch of songs to play "ok" (but avoiding many others because I didn't know the chords, or the shapes were too difficult for my slightly arthritic hands). Then I saw Fretboard Wizard, and decided to give it a try.
Tony's approach of starting with (and always going back to) the "musical alphabet" has solidified in my mind the connections between scales, keys, chords and I now feel confident that I can figure out how to play just about any song I want to ... still takes me some time, but my confidence level is there. I'm still working on the course, taking my sweet time because I can, and because I'm loving the journey.
I highly recommend Fretboard Wizard to folks who can play a bit, but need help tying it all together and making the leap to *understanding* how to get better. Thanks, Tony.