I'm glad he kept his mind till the end, and enough of his health that he was able to do what he did. I am not personally that crazy about his artistic vision, but I admire that he was able to spread it as widely as he did.
I wasn't all that wild about his fanatical obsession with canon, but it was actually an integral part of the business plan. He didn't want Spiderman fans or Thor fans or X Men fans, he wanted Marvel fans, so things had to be consistent and you had to buy several comics a month to keep up with the story.
He's the only reason comics are mainstream, really, and he's the reason Marvel is the go-to name in the industry.