Mach vs Restify

Mach has some pretty cool streaming functionalities built directly into it, if your web app provides any audio/video/data streaming features, you can consider using Mach to build it.

Since Mach already is asynchronous (stateless) which means your logic is implemented by using promises (then objects); hence your functions are pretty independent and composable.

No complex layers between plain HTTP requests and the corresponding JS functions invoked. Which in turn means each GET/POST/PUT or any other HTTP request is directly mapped to a Javascript function. Hence leading to a huge increase in performance for your app

One of the distinguishing features of Mach is it's robustness, errors won't be terminating your complete app, instead they'll bubble up so you can handle them gracefully.

Like most of the Node.js's core, Mach is an asynchronous web framework too. Each response (of a request) can simply be hooked up to a then method so that its result or the reason for failure can be retrieved after the action is complete. If you're wondering what async operations are, here's a pretty good explanation for you

DTrace helps you with troubleshooting and building robust RESTful applications.

As the name suggests, Restify is devoted solely to creating an elegant REST API. The API is the core of your site or service, so it makes sense to use a framework that excels at that.