As a mere mortal non-musician Lindsey Buckingham fan, I have little to add to this analytical discussion of Lindsey's competence and merits as a musician/guitarist/songwriter/producer/human being, etc.
For me, Sodascouts said it best:
It's so much easier to analyze whether somebody can pick faster or cleaner or whatever than the much more subjective "special something" that takes technical skill to the next level. I believe Lindsey has that "special something." It's like faith, you can't touch it or explain it but you know it's there and you know it's real. :-)
And, in the course of the conversation about Lindsey's departure from the band in '87, I was reminded of this excerpt from Singers and Songwriters:
So he eventually left Fleetwood Mac altogether, and they replaced him with two singer-guitarists. It was an attempt doomed to failure; you can’t take the heart out of a band and replace it with mere musicians.
Of course, that's just one writer's opinion.
Barbara