John Mayer's playing style is a bit different. He uses a lot of weird chords and a lot of blues riffs.... The biggest thing about his style is that it's very sloppy (even though he makes it sound clean and effortless) he grips the neck and uses his thumb to fret the E string a lot of times... Songs like "Who Did You Think I Was" he plays very loosely and sloppy... I would say the most prevelent influence on his style is Stevie Ray Vaughan especially his phrasing in his solos... Neon is a pretty tough song to get a hold of because it's pretty much mostly sweeping... It makes it easier to learn his songs if you can see him play it. He uses some weird hand positioning that is really conventional... even though he went to Berkely... that doesn't mean he's a proper player. That's his style in a nutshell I suppose... Also practice your travis picking if you want to get that popping acoustic/percussion soudn that he gets in a lot of songs. Similar to Jack Johnson...