From what I have seen the tooling is definitely great. I am not the worlds biggest fan of Ruby on Rails, but one aspect I have always liked is the scaffolding. Being able to generate the skeleton of an application from the command line without needing to glue anything together or read documentation on multiple plugins.

Don't get me wrong, I love working with React.js, but it isn't a framework and aspects like dealing with data, API's and other more functional aspects can take a lot of time to get working with React's way of thinking. React also requires a certain degree of glue-fu to get it to the same place something like Angular, Ember or Meteor seems to be. I think Meteor could be a nice down-the-line framework. For my next project, I'll give it a shot. I have a friend who has been building something with it and he seems to absolutely love it.

Having said that, if you want to use React and Meteor after reading through the documentation it seems they make it easy to integrate with other libraries and even frameworks. I even saw they mentioned you can use Meteor with AngularJS (which is crazy), but cool nonetheless.