WSO2 Application Server - REST Service, deploy as Application or Service?

If I have some functionality I want to expose via REST in the WSO2 Application Server and it seems that I have two main choices:

• Deploy as a JAX-RS Application
• Deploy as a Service

When deploying as a service, it appears that I have options for Quality of Service that don't appear to be available for Applications.

Question: If I am creating a REST based functionality from scratch, should I prefer to design as a service rather than as an application, because the service has more flexibility?

In WSO2 Application Server there are two approaches to create RESTfull services.

1. Create RESTfull service using Axis2, then you should deploy them as "service"
2. Create JAX-RS spec based service using CXF, then you should deploy them as "JAX-RS" applications.