Since77 nailed it. If he's given half a chance, he's still the best finisher we have. However if he's given no quality ball, or trying to help out halves who play east-west, he'll struggle (like anyone).
Gitano has summed it up better than me - he's the best finisher we have, and he hasn't had decent ball for years. Any winger would have struggled at the end of our impotent attack.
Nightingale has never been a winger to sprint 50 + metres for a try. Give him good ball 10-15 metres out and he'll get the job done better than most.