Basically yes. As a big big coffee drinker I have a really high tolerance to caffeine, often I will sip on a cup during my workout even after having taken the 400mg. The ephedrine on the other hand I'm pretty sensitive to and find that 24mg is a little too much(jitters/nevous energy/sweating etc..).
B vitamins are commonly found in high dosages in lots of energy drinks (5hour energy and the "niacin flush") and are also used by a lot of people as a study aid/cognition enhancer. Sometimes I take them before school and do notice a subtle "concentration" effect- This is why I include them.