His new material is his best, or rather, his only decent material. His pop hits are so sickeningly syrupy you could vomit, he has a horrible voice for blues (never mind the steve jordan popcorn snare that added to the ruin of most of his trio stuff). I think the dude has finally found his niche. Go John.
I never heard anyone say this, but I did see that Mayer once wrote that Jimi is the "common denominator of every style of popular music," which is easily one of the most howlingly false/stupid statements I have ever heard.
Anyway, he's a phenomenal guitar player, I just don't really like his music. If Weir, Lesh and company will share a stage with him, I figure he's probably "okay."
If that publicity shot bothers you, stay away from the videos from his new album.
Like @Tele-friend said, it's an intentional, and I would argue loving, homage to the slick 80s pop/rock of Mayer's youth. Mayer clearly has a sincere appreciation for that genre but is being more than a little tongue-in-cheek as well.
Personally not a fan of Mayer's music, just not my thing, but I appreciate that he's playing around a bit with his image. There's a small part of me that wants to think Mayer's got an inner weirdo waiting to bust out a brilliant album, but this far into his career I suspect that's just wishful thinking.
Comparing anyone to Jimi or SRV is a recipe for guaranteed disappointment.
John Mayer is a demon on guitar, look at any of the videos of his live blues stuff on YouTube. More importantly is he's an outstanding songwriter and guitarist in his own style. His new album is my fav it's very 80s influenced but without being contrived recycled 80s riffs.
He's covered a lot of genres and all with authenticity.
And neon is the envy of most men as being an unbelievably difficult song to get eight, and Mayer wrote it, and plays it while singing like it's nothing.
You don't have to like his stuff, it's not everybody's thing, but damn is he amazing at what he does.