You can end up with a hard to maintain code with knockout.js if you don't structure it well. I found https://github.com/danderson00/knockout.composite recently that seems to adopt a similar philosophy (pubsub) to what Flight does while keeping the benefit of knockout.
I've used this knockout extension to great success [1]. It's intuitive, it leverages knockout's internal pubsub, and fits in with the KO ethos. It can be used to synchronise observables across models (which is awesome as it's events without overhead), or as a general purpose event system.
Ryan is one of the core contributors to knockout, by the way, so you can be assured of its quality.
