Was he quick by today standards though? His contemporaries seem slow compared to Bale or Traore and quite slight in stature. It may be the poor film of the day, but the likes of Matthews always look quite pedestrian.
Its virtually impossible to compare players from different eras. Todays footballers are probably the quickest and fittest ever.
I am not old enough to have seen Cliff Jones play in the flesh, and there is very little really good quality footage about to judge, but from what I have seen he was certainly quick for his time and as Smithy said he was a very direct runner with end product too. You also have to remember that he played in an era where defenders could and would hack you down frequently without the fear of being sent off.
Looking at Cliff now you can see that he has clearly looked after himself, so its likely that he was one of the cleaner living players of his era and maybe have been ahead of his time from that aspect.