Does it make sense to use Entities as JSF Backing Beans? 

@Entity
@ManagedBean
@ViewScoped
public class User {

    private String firstname;
    private String lastname;

    @EJB
    private UserService service;

    public void submit() {
        service.create(this);
    }

    // ...
}

Or is it better to keep them separately and transfer the data from the backing bean to the entity at the end?

@ManagedBean
@ViewScoped
public class UserBean {

    private String firstname;
    private String lastname;

    @EJB
    private UserService service;

    public void submit() {
        User user = new User();
        user.setFirstname(firstname);
        user.setLastname(lastname);
        service.create(user);
    }

    // ...
}
jsf entity backing-beans
Edit
Report