A lot of people are spewing a lot of well-founded hate at the node platform, but the comments are missing a lot of substance.
Node is just ok. What it is amazing at is doing lots of asynchronous IO, and has some libraries that make this pretty easy (i.e.: async). When all you need to do is read files and hit APIs and write files it's great.
Now node has a lot of shortcomings. For one, it's really not that fast when doing actual processing. If you need to do any kind of remotely complex calculations, including things like html template rendering (handlebars), data structure transformations or even like zipping/unzipping, it's slow as a dog. And since data calculations aren't IO, async operations actually start to slow you down. AND, unless you explicitly do things in an async manner, your whole node process will lock up and only that one task will execute, which can cause all kinds of latency issues with your app.
One can argue that ruby, etc suffer from the same fate and that's why you have multiple processes running. But because of node's async nature, if you are using a web framework like express, each process will potentially be handling multiple clients. And process that's processing will cause those clients to get slower responses and any crash will kill all of those clients.
There is also the mess that is npm, where it becomes very easy to have a 700MB dependency directory which SUCKS to deploy to multiple servers.
That's just my experience as a node Dev for the past 18 months.