Hey there, You will definitely see the added benefits of using Big Bud alone. Overdrive as I am sure you know is for weeks 5-6 to push flowers into another surge of growth near the end of flower. Where as Big Bud is used in weeks 2,3 & 4. It is a bloom stimulator that works in conjunction with your base nutes. You don't need Overdrive, but if you want use the right supplement for late flower this is the one. It will help flowers get larger. Since it is only used in weeks 5 & 6 it lasts for a while as it is not needed that often. The difference is considerably noticable. If there was only one more product I would add it would be Sensizym. This product contains enzymes which are beneficial in removing dead root matter and turning it into usable matter for your plants. It also enables you to re-use your medium.