The main reason to not use it was scaling but It's evident the meteor guys are working on that for the 1.0 release. (See https://trello.com/board/meteor-roadmap/508721606e02bb9d5700...)
Hopefully they do this well but I feel from their work before they will. I've been using Meteor since it was sub v0.2 and its just improved each iteration.
First it was the license, then authentication, then it was routing, then its ability to play well with JQuery. Slowly all of the issues with it are disappearing.
One thing I like is in meteor code is isomorphic. And on the server I'm not in the callback hell I was having with node. So there are evented fibers that do all this stuff and the code remains clean! Best of both worlds.