Marionette does an incredible job of managing complex view structure, but it feels like a stronger tool than necessary given the requirements of the Borrower Funnel. Using a combination of React and Backbone.router would reduce the amount of code, but still give us the ability to manage validation and views. Below are some notes about this alternative
Keeping developers away from manipulating the DOM directly. It wraps each HTML element in a React.DOM object, making it a bit easier to work with (we found it to be very digestable). It also allows for very reusable, and easily testable, code.