You don't only want to get stuff done quickly, you would love to code without nitpicking about the usual roadblocks: eventhandling, dom manipulation, template rendering and the growing list of problems along with the complexity of your project.
If you could simply focus on what you could do best and still have the power to create interactive UIs, you have come to the right place.
On a personal note: RiotJS served me fantastically as introduction to JS based MVC/MVP systems where Ember, Angular, Backbone and similar failed to persuade me into bearing with its complexity. It's enticing how easily you can pick up Riots few simple API Methods and write apps in extraordinary speed. Even as newcomer to JS!