I think a lot of the disconnect is that I'm not much of a stat guy; there are very few instances where I find them really useful.
For the RB position when so much of the result is wholly dependent on the 10 other guys around you, stats hold little water for me.
I think he's a better pass catcher because he's more instinctual at finding holes in zones, and he's smoother at tracking the ball, securing it and transitioning upfield.
If I look at that, it tells me that Moss' runs are coming in predictable situations with loaded boxes (i.e later in games with leads where the Bills have indeed used him frequently, as well as obvious short yardage situations where the Bills have also used him frequently) and he's getting contact right near the LOS, while Motor is getting carries in more diverse situations that allow him to get some momentum going forward before he's dealing with tacklers.