Between the 2 products not at all. I have been using boosters for the last 3-4 years, so I haven't tried not using them since my gardening skill has increased. I did see an increase when I started using them, but who is to say that I could not do the same thing with now knowing the ratios the plants like at certain times. I have gotten in the habit of using them, I don't find it complicated using multiple products, and the cost is not a big deal to me. I have not once on RIU suggest anyone use a particular booster over another, but I have experience with quite a few to give an honest opinion on how they perform compared to some of their competitors. For example I would use big swell over KK if it wasn't for the higher dosage rate of Big Swell(2-4ml of KK, compared to 10-15ml of big swell).
I can say though that I can hit the same yield with many different booster no matter the company. I now focus more on how they affect the finished product when it comes to look, taste, smell, and oil production.