what does it accomplish for you that normal server rendered framework doesn't do for you?
when you build a meteor.js app you need phantomjs to get it indexed...it won't work on older browsers....the list goes on
I just have trouble justifying why I would need to write my next app using meteor.js
Using phantomjs to index your site has not caused any problems for most of us building apps in production for the past two years. From an engineering standpoint there are better alternatives such as server-side rendering (btw, there is a Meteor package that does this: https://github.com/meteorhacks/meteor-ssr), so outside of performance considerations this isn't a super big deal. A lot of Meteor apps also aren't Google-facing but instead apps that you use after log in, where Meteor's advantages have the biggest effect on one's productivity.
Meteor works in every evergreen browser and quite a few older ones. It will fall back to polling if there is no support for websockets and the Blaze view library works in IE8+.
I recommend just trying it out. It takes no time to install and get your first app started (<1 min) and you will immediately start to see the benefits. Come tell us more about your situation at forums.meteor.com and maybe we can help!