Bob Lewis was my on and off guitar teacher for close to 10 years in Wilkes-Barre Pa. I started with Bob at 12, gave up (my first mistake!) taught myself came back at 16 and studied with him for four or five years. In those four/five years I learned General to Moderate level Music Theory including Diatonic Theory, Chord building Theory, scale theory, chord progressions, picking posture ect.
I could go on for days about what I learned but the fact that the social climate of those thirty minute weekly sessions was always calm, relaxed and full of fresh ideas. Every concept was very straight forward and if it was a bit complex (such as modal guitar solos,) Bob would explain it in a way that made sense based on our prior sessions (aka, he actually adapts to your idiosyncrasies )
At any point when I hit a wall Bob was immediately finding ways to climb over the wall. If it was not in that session by next week he would have devised a plan to work on overcoming the daunting idea at hand.
Aside from the straight forward learning methods, if you go into a lesson with Bob off the cuff without any goals in mind for your development he can easily break down what you need to work on and how your should work on it.
Also... Bob can shred...so fear not fret board wizards!
As for what could have been better I have not much to say. The fact is with most good teachers your own ignorance is usually the problem and when i started at 12 by the time i came back at 16 I realized that Bob's method was not flawed, it was my attention span.
The Man is a brilliant guitar player and all around musician and is well worth your time.