I'd say his passing on the run is about like his passing in general. Looks spectacular on one play, substandard a few plays later.
As has been said many times, gunslingers like Newton are rarely consistent with their ball placement. You coach them to be as accurate as possible, but you're never going to make a Tom Brady / Aaron Rodgers pinpoint deadeye passer out of this type of quarterback (Favre was scattershot right up to the end).
What you're shooting for with a gunslinger is for more of the balls to be catchable than not. If you can get that and combine it with receivers who are good at adjusting to the ball, you can win a lot of games.
That's the goal.