It's funny, because I have the exact opposite reaction. I think he makes good points, but ruins it in that his own style is cluttered and more complex than it needs to be. It's still great advice to follow: I see it as "do as I say, not as I do."
But the substance of his advice is good, and anyone who enjoys the style would probably benefit from reading it. It's just kind of ironic that he's unable to apply his own instructions.
It's been a long time, though, and the book apparently has many fans on this board who surely know it much better than I do. But no, less technical and more discursive than Strunk & White.