My previous blog post on Ember was one of our most popular blog posts of the year -- there are clearly many people interested in learning Ember. Many of them are coming from a Rails background. I think coming from Rails helps, but there's still a lot to learn.
Trek, an Ember core member, has said that “Ember applications start out with a complexity rating of 4/10 but never get much higher than 6/10, regardless of how sophisticated your application becomes.” I agree with that. Some things in Ember are easy, like understanding the way Ember Objects work. Other things are more complex, like routing and communication between the various objects in the framework.
But once you get it, you get it, and you realize how simple the whole thing actually is. So my advice to aspiring Emberistas is to do my tutorial, build some stuff, and play with the framework. See what things do and what they don’t. I’m happy to help if you have questions along the way.