Well, I've seen Hendrix half a dozen times back in the day. In fact, I saw his first NYC gig (I believe right after Monterey) when he opened for, of all bands, the Young Rascals at the Schaefer (later Reingold) Music Series in the Wollman Rink. Blew the house down! The Rascals came on and the crowd started chanting, "Hendrix, Hendrix, Hendrix". Felix looked a bit perturbed. Saw Hendrix at both the Village Theatre and Fillmore East, which, of course, were the same place. It wasn't enough to hear the guy on vinyl (or digitally). In person he made it look so easy, so layered. And I was a big fan of Mitch Mitchell too, of course, being a drummer.
I've seen Clapton and the Cream (their first US performance was at the Murray the K show at the old Parmaount) may times, Clapton is God, what can I say. Jeff Beck I saw in London with Rod Stewart as his lead vocal, a great technician. Zappa was a talented musician, but I wouldn't put him in that company. Zappa's genius was in composing and writing. Still, loved that guy.
But it's one thing to learn and improve on, but it's another to innovate. These guys were innovators. Gotta give them points for that.