So, the biggest thing that can't be worked around is that the number type in Javascript doesn't support arbitrary-length integers. That means that you can't blindly trust numeric IDs for resources (though it'll take you a while to hit them)--instead, you'll have to do things like specify string versions of those id's. Twitter ran into this, I believe, and it's something to be aware of.
The other disadvantage of using Node is that the ecosystem is still not completely agreed on what to use--for my 0.02USD, I'd look into HAPI + Swagger.
Also, if you don't know about promises or generators, you're going to write really really ugly Node code. That said, it's pretty easy to pick up.
