I think most will admit he isn't much of at outright attacking fullback.That's rare, Halfpenny getting some criticism. He's become a bit of an overrated player these last few months.
he does like to attack on the counter down he touchlines, such as Samoa RWC and Lions test 3. I think he is still developing as a fullback, but his biggest asset besides kicking from tee is excellent positioning to received deep kicks. I'd like him to join the line a bit more, and use his pace that we know he has.