Good points, Jon. With "major/minor sound", Griff is giving us the information to sound great instead of just good.
One thing that makes the major/minor thing difficult, I think, is that most of us expect some huge difference in sound. In reality, the differences in sound are kind of subtle.
If we look at MikeS's diagrams above, many of the notes are identical and others are often just a half-step apart. Putting a "major" twist on things is often just a half-bend or a sliding note away.
If we learn Griff's solos, we get these subtle enhancements for free. We also learn how they sound. "While it's great to know how to fish, when you're hungry, having one fish is pretty good." - Smokestack
Winging it, it's sometimes hard to know if we've accomplished the goal or not, but use of the proper pattern at the proper time will assure it is so, even if our ears aren't yet trained to detect it. Having the right licks in the right spots and their corresponding sounds in our heads from the lessons can only help.