I like Knockout, and have used it in several production systems. It has been a tremendous help in getting rich interactive UI on web apps. Having said that, t

I like Knockout, and have used it in several production systems. It has been a tremendous help in getting rich interactive UI on web apps. Having said that, the mistake I made early was to use ko.mapping.fromJSON and fromJS to blindly generate the view model, which turns every field into an observable. It was very easy to get going and get it working fast, but I ran into performance problem later on with hundreds or thousands records. The advice to take the time to build your own view model and decide which field needs to be observable and which field can stay plain old Javascript object is very sensible.