CXF 3.0 implement the JAXRS 2.0 client API, it makes your code can work with other JAXRS implementation without changing anything.
But if you are still using CXF 2.x, you need to chose between the Proxy Based API and WebClient API.
The Proxy Based API is much like the CXF JAXWS Client API, you can just invoke the service from a Proxy which implement the interface of SEI. It has some shortcomings, you cannot specify the http hears or write a generic client to invoke the different JAXRS services.
With the help of CXF WebClient API, you can invoke the JAXRS services in a normal HTTP client way, which just fill the gap of Proxy Based API.
You can find more information about those clients API here.