What is best practise in Spring when creating a new user with custom attributes...to extend org.springframework.security.core.userdetails.User or to create the User in the UserDetailsService (this is the approach taken in the IceFaces tutorial).

public UserDetails loadUserByUsername(String username)
        throws UsernameNotFoundException, DataAccessException {
    AppUser user = userDAO.findUser(username);
    if (user == null)
        throw new UsernameNotFoundException("User not found: " + username);
    else {
        return makeUser(user);
    }
}

private User makeUser(AppUser user) {
    return new User(user.getLogin(), user
            .getPassword(), true, true, true, true,
            makeGrantedAuthorities(user));
}