There's a mix of rock/blues rhythm exercises, leads and fingerstyle acoustic exercises.
Why it's cool is....we've a blues challenge on and there some cool bits if you need some inspiration AND each exercise has a soundcloud example, so it's not just the tabs (thankfully!).
https://www.guitarworld.com/lessons/john-mayer-12-playing-tips
Excellent post
Is it just me or is lesson 12 physically impossible?
studmissile I've havn't tried much on the list - and at first and second glance, I'm a 100% with you. The tab is a stretch and the ''thumb over neck' thing it isn't what I thought (they notated only one bass note p - index finger?)
But, here's a screenshot. What, in the name of all things Tobin Abasi, is this man doing with his index and middle fingers so far behind his thumb? These jazz chords are truly getting ridiculous 
