I mainly watched Torres in Liverpool era and provide my few thoughts based on this.
Torres had good pace and excellent first step at that tie. Vidic always had hard time to match him. Liverpool mainly played counter attack. There were more space at front for him to run. Kuyt, who had great chemistry with Torres, was a very hard player and gave Torres a lot of help. Torres had good faith at that time, and always tried to dribble past opponent one on one. Probably, after some injuries, his first step may be slowed. Just a little difference on this can harm his game a lot.