As someone who has tooled around with Meteor a bit, and also digging into the other platforms (although I haven't messed with FlatIron yet, despite being a Nodejitsu customer/fan), I think Meteor has a huge sweet spot in the Enterprise world. It really does abstract a huge amount in a way that is very un-Node, but that has some great pros when it comes to time saving. It is unbelievable how quickly a professional app with authentication, bootstrap, email (integration with mailgun out of the box, or your own) can be built. A lot of times in my day job as a data analyst, I just need to quickly get a tool deployed for my team to work with, and I'm not trying to be "pure" and worry about being able to npm install the latest MongoDB to Postgres synchronization module, or something like it.

Don't get me wrong, I'm very excited about where Rendr will go when they finally get it ready for prime time, and I'm trying to get more comfortable with Backbone in preparation for it. But the ease with which I was able to quickly build something in Meteor makes a stark contrast with what I'm having to do with Backbone/Express combo.