I've tried a number of NodeJS servers [expressjs, sails, meteor, hapi]. I cannot say that they are all completely different or that they are completely the same. They are what they are.
- expressjs comes from a long line of connect experience.
- sails feels a lot like rails with some really cool features like auto subscription, socket.io, and the browser console.
- meteor is a complete departure from the others. It's a complete server but it's also a complete platform. More so than the others. It's also it's downside. It already includes bootstrap but what version? Then there is the customizations too.
- hapi is an odd duck. It's like a traditional app server but then they go a long way to help you handle some of the edge cases like client ans server side cache with a simple config setting. But then when you look at the add-ons they are so very incomplete.
The documentation and useful examples are another pain point:
- expressjs the documentation is just barely adequate when supplemented with the code. But then the examples could be better.
- sails has a great screencast but the documentation is missing some key elements like how to deal with static docs. While you're likely to figure it out you may feel abandoned.
- hapi has plenty of words but only covers a fraction of their server. When you install the module you'll see buckets of modules installed and just not enough to read.
One thing I did not like about meteor is that it did not use NPM. Not that NPM is without warts but at least it's consistent.