When did this happen? Clearly I must have missed it...unless you are considering 20-25 yards as "ripping off a long TD run". Most Devin has is a 51 yard and a 40 yard. But a 75 yarder is out running a defense, which would take "speed" to do. McCoy has taken anywhere from 45-75 yards for a score . Lol, at you implying Singletary has "long" TD runs comparing to McCoy.
McCoy's ability to to out run the defense for 75 yards alone absolutely makes him a speed back. Not sure if you're just trying to find anything to argue about, but only other thing you can describe him as would be "shifty". But was absolutely a speed back that was a threat to take it all the way