Nice. I wish the teardown had gone further too. I like taking stuff apart, and putting it back together, but when it comes to top-of-the-line, or even midrange camera lenses, I can only live vicariously. Plus, camera guys seem to take good teardown pictures.
I have the "cheap" f4L 70-200L non-IS, circa 8 years ago. I wasn't necessarily in the market for an L lens, but it wasn't all that much more than the wider-ranging basic lens, so I decided to go for it. It is my favorite zoom lens, by far. The IQ is fantastic.