Rocky- The reason why most people stick with Test Only for their first cycle is so you can distinguish sides from one another. Example: Sust is made up of more than just one compound. Thus, if you start having sides you have no idea which compound is truely making them (which is something that you WILL want to know if you continue to use AAS). Also, keep in mind that a TEST ONLY cycle will allow you to familiarize yourself with the whole pinning process (where the exact locations are, timing, technique etc). Also, using something like SUST is more advanced because of the Prop-which has a tendency to hurt while/after injecting. And if your not familiar with these effects you will not know what is normal for your body or not.
G' LUCK!