Yeah, being fast is really easy if all you do is spit out files. When you actually have to do processing, things get a bit more difficult, and a system like Erlang becomes more compelling.

It all depends on what sort of compromises you want to make in terms of speed, ease of programming, and the expected amount of traffic, though.

I'm not sure about Erlang. I don't know this language and the protocol I designed uses binary encoding. Support of JS and python is planned, especially on the client side, but come with a performance overhead which is not very attractive when it comes to service performance.

Using a language you know is probably a good idea: better to get something up and running and worry about making it blazingly fast when you know you need to. Erlang handles binary data quite well, but if you don't know it, you don't know it.

One of big benefits of the async model that ngninx uses i that it can keep many open connections. If you don't have many long running open connections (I/O on the socket), then going that route doesn't really help as much.