What are (potential) disadvantages of using meteor.js? [closed]

Well, I would advice you have a play about with meteor and make the judgement yourself. It really depends on what you wish to develop

Certain constraints I have found are

• Meteor comes bundled with only mongodb. Other database support are planned for later releases

• No model/object form binding (in road map)

• Package system is not npm (although Meteor is built on node) and is closed to community. All meteor packages are developed by meteor themselves

Regarding performance, I found this article helpful

Here is another link to meteors roadmap

From my experience, I would say the advantages I have found outweigh any disadvantages at the moment

Having built client projects in meteor there is 2 things I immediately found hindering about the system:

1) No native support for MSSQL / MySQL or in fact any other DB than MongoDB (which jamin mentioned). That said, it sort of makes sense as to why this is the case, as a NoSQL solution with an easy to use JS api makes sense over a clunk RDMB database. However there is a plugin called Meteor SQL which supports MySQL at the moment https://github.com/drorm/meteor-sql

2) No native support for windows - Meteor is only released on linux & OSX meaning us windows users are out of the loop. There is an unofficial windows build on http://win.meteor.com but it's stuck at 0.5.9.

I probably wouldn't recommend building full sites out of Meteor yet as well due to it's various instabilities - https://github.com/meteor/meteor/issues however in a controlled environment it's perfect.

Also bear in mind Meteor have achieved an $11m funding grant - http://venturebeat.com/2012/07/25/meteor-funding/ meaning it will continue to improve and grow.

A huge problem for Application development are missing things like validation or translation.You have todo everything on your own an include and use many external sources.NPM support is not optimal, for backend usage ok, but in frontend a hack.