I have used the Spark View Engine on some ASP.NET MVC projects (all non kooboo projects actually).
The big advantage is imho the possibility to define custom bindings, making some "programming" tasks very easy for designers.
For exemple, to define a link to a page you could use <a page="Home">Home</a> and a binding would transform it to the page url, you don't have to type any C# code.
I think most of the situations where you need to type code in Kooboo can be replaced by some similar things.
It's just an idea but it could be nice to make kooboo accessible to a wider public (not only asp.net mvc programmers).