The Beatles were masters of composing, arranging and producing records and George Martin was an important part of that machine. If you listen to their finished-but-rejected versions of Norwegian Wood and Ob-la-di Ob-la-da you will know just what amazing ears and high standards they had. Most other bands of the time would have been thrilled to have produced either of those tracks. The Let it Be/Get Back films show the process it takes to get there, minus the very important George Martin contribution. The results do not compare to other Beatles offerings and much of it is no more exciting than being at some other family's Thanksgiving dinner. I enjoyed the Jackson doc as it was so much better than the old Let it Be film (that one is more like being at another couple's breakup). The difference between the Let it Be and Abbey Road LP's is huge and it is because George Martin said, okay, we'll do another one but only if we do it the way we used to. I sometimes wonder if the White Album wouldn't have been better if they had taken George M's advice and made it one really tight LP instead of two.
I don't think it's fair to compare George Harrison's guitar playing to that of Eric Clapton or Robbie Robertson. George was a master of short solos that were perfectly suited for the Beatles songs. Robbie and Eric can do that but they are accomplished jammers as well and George was not. That said, I love Robbie's playing but I don't think he comes off as well when side-by-side with Eric. Not many people can stand toe-to-toe with EC and look/sound good, although Jeff Beck certainly could. And Hendrix blew them all away. I appreciate all those guys for what each one brings to the table. Each has his own style and nobody does it all.