#3 Soy Burns Longer
Soy wax burns at a lower temperature than does paraffin wax, making the same amount of candle last longer with soy. Plus, a good soy candle should burn off every ounce of wax in its container while paraffin candles tend to leave a good amount of wax at the bottom.
#4 Soy Releases Scent More Gradually
Because of that lower burn temperature, the fragrance in a soy candle tends to disburse more gradually than with a paraffin candle, which may burn all the fragrance oil off at once so that the candle loses its smell for the rest of its burn time.
#5 Soy Is Easier to Clean Up
Any errant spills or drips are easier to clean up than with paraffin, and at the end of a container, you can simply wash it out with soap and water, and it's safe to be repurposed however you'd like.