I just wish it had proper API documentation. There are no real docs, only examples/tutorials, this can be quite frustrating.
If you've never used data bindings in HTML/JS, you HAVE to give this a try.
If you're still using jQuery & other manual event handlers to change the state of your UI, you GOTTA try it!
What is missing from http://knockoutjs.com/documentation/introduction.html in your opinion?
BTW, I think Knockout is just prescriptive enough to get a pretty tight maintainable codebase, but without causing another layer of wrapping/complexity when you want to use existing JQuery components.
Your app can out grow knockout and then your stuck rolling your own location provider,dependency injection and more.
2-3 years ago knockout was a breath of fresh air but know its just old and dated technology.
And compared to the bloat that is angular and especially ember, I find knockout strikes with simplicity and 'keeping-it-simple'.