Longstrider, I think what you are comparing is the tinder, not the firestarter.
Char cloth will ignite every bit as easily from a ferro rod as with a traditional flint & steel. Actually, the ferro rod would be easier because, if used properly, it throws significantly more sparks, and the sparks are much hotter. I can think of no instance where a traditional flint would be superior (or easier) to the use of a ferro rod in igniting ANY kind of tinder. While magnesium flakes can be a pain in windy conditions, that can be overcome by shaving them onto the adhesive side of a piece of duct tape.
This is not to say that learning to light a fire with a traditional flint and steel is a useless skill. As a survival skill, it is useful in instances where you find yourself without any other firemaking method, i.e, where all you have is steel and find a hard rock. Of course, you'll have to find some natural tinder as you wouldn't be able to rely on char cloth in this instance. Given the lower temperature and smaller volume of sparks, flint and steel is not as efficient igniting natural tinders, especially in adverse circumstances. therefore, I would not rely on this method as my primary (or even secondary) survival firestarting method. Primitive skills folks also value this skill for nostalgic reasons that are independent of their objective efficiency.
-- FLIX