I watched a video of Jing Chen on the Facebook team explain problems with MVC complexity. I felt like what she was saying made alot of sense and I have heard that React.JS can do alot for a simple library.
I found this post which explains different ways of using React.JS with Rails and Flex. (Flex is the MC in MVC and React is the V), however they all seem to have pros and cons and it is not clear what is the best approach. The third approach seems to be to use two servers, Rails and Node. That does not seem optimal at all.
It seems like to use Flex you need to use Node, so it appears if I want to learn more about Flex then I have to possibly focus more on Node as a server …