The idea is to get over the jitteriness as quickly as possible and benefit from the energy and thermogenic properties of the combination. I personally use diet fuel by TwinLab because it also contains L-Carnitine, Chromium, and Hydroxycitric acid which are, of themselves, potent fat burners that do not add any stimulating effect. Other good products out there look like Xenadrine or Hydroxycut. These two also contain aspirin though, so beware if you have ulcers or a weak stomach. By the way, any negative info you are hearing is probably from people who either increased their dosage too fast or are intolerant of stimulants such as caffeine, ephedra, etc.