Here’s a proper synopsis:
“He was one of the first to use distortion (the heavy rock guitar sound) and other sorts of audio effects in a truly effective way. He wasn't the only person doing it, but he's considered the best of his time at it, and generally everybody after started trying to copy him.
From a purely technical perspective, he wasn't necessarily unique, though he could certainly keep up with the other top guys of his time when it came to "shredding." He did pioneer (or, really, popularize) a few techniques like using the thumb of the fretting hand, which not many other guitarists of the time were doing, but is now pretty much standard (the guitarist from RHCP and John Mayer do it a lot, off the top of my head).
It was really in terms of raw overall musical ability and sensibility where Hendrix outclassed other guitarists. There isn't one thing you can necessarily point to that he did better than absolutely everybody else, it's more that he could do everything you would ask of a guitarist at a world-class level. Because he was so versatile and so damn good at everything, he was able to play in a way that other guys couldn't. A really good soloist like Clapton, for example, can impress you during the lead passages, but their rhythm sections are less inspired. Hendrix's leads might not have been as perfect as Clapton's, but he could drop into a rhythm section and blow Clapton out of the water.
Basically, with most guitarists, I could give you a two-minute clip of them playing, and you'd pretty much know what they're about. With Hendrix, you have to listen to nearly his entire body of work to really appreciate how complete his mastery over the instrument was.”
Clapton, Beck, Roy B,, Trout, Vaughn Bonamassa, Guy, Young, Santana all paid serious tribute to the guy.
But what do they know.