As a relative newcomer to web dev, I find Meteor very challenging to work with. It's got too much magic going on. Part of that is the simple fact that the documentation, while sufficient for pros, simply doesn't hold your hand. At all. And beyond the documentation there's a dearth of other resources for finding out how to do things. The community is too small to be effective, and any books which have been written are out-of-date already. Answers to questions on StackOverflow normally don't even apply anymore because the platform has changed so much. This is all very typical pre-1.0 stuff, so the point is that I'm not sure Meteor is maturing fast enough. It might be too late to the party once it finally stabilizes.
Either way, I strongly dispute the implied claim that Meteor is easy to learn. It certainly is not. Rails makes a lot of intuitive sense--at least to me--whereas Meteor doesn't. As the author mentions it has the whole kitchen sink approach going on, and that makes it very unapproachable to someone like me...because it's difficult to make sense of unless I understand all the components on which it's built.
So is Meteor cool? Absolutely. And it could be great if it matures fast enough to still be relevant, and if it manages to be associated with some truly tremendous learning resources which not only display its potential, but assist in learning the intricacies of the platform. I worked my way through the Discover Meteor book and was impressed by all the magic Meteor slings, but I didn't really understand much of why and how it worked.
So we'll see. But for now, Rails is untouchable.