Whether it be with raw stats or more advanced metrics, it's not hard to see who is being productive, or efficiently productive, just by looking at numbers. However, it's a mistake to just look at either set of numbers and make sweeping conclusions.
There are lots of variables that go into the success or failure of a player, as has been discussed here many times. There are also circumstances in which a player may be failing overall as an individual player, but still impacting the game and his team in a positive way. We know that the first step in getting out of a hole is to stop digging deeper, because the climb just gets more and more difficult.