More seriously Node.js has some pretty major performance problems, like the fact that it's single threaded. You'll make excellent use of one core, but that's about it. It looks great on I/O bound request/second benchmarks, but as soon as your code needs to do meaningful work it doesn't scale anymore. The solution to that is to spawn multiple node instances to make use of the actual machine resources, but now you're on your own and why did you bother with node.js then in the first place?
More seriously Node.js has some pretty major performance problems, like the fact that it's single threaded. You'll make excellent use of one core, but that's about it. It looks great on I/O bound request/second benchmarks, but as soon as your code needs to do meaningful work it doesn't scale anymore. The solution to that is to spawn multiple node instances to make use of the actual machine resources, but now you're on your own and why did you bother with node.js then in the first place?