Bought it last year from Gan. Used to be Gewo efficient energizer and only available in purple. The booster was really thick and really easy to overboost, because it took a really long time to absorb. It actually is best to wait 24h on each layer before continuing.
This booster softens your rubber a little less. However, as Ng said. There is not that much of a difference to any other booster in the long run.
Mystery solved!
I bought Haifu national yellow before. It is ok. Not sure it is worth the price difference.
I have also used Falco Tempo Long Booster and it worked just fine.
So I have settled on Haifu regular yellow.
I watched ThePongProfessor's booster series on YouTube (it came out during COVID lock down). I don't know if I agree with his reviews or not.
Table tennis equipment involves the rubber (FH and BH), the blade (all wood, inner carbon, outer carbon), the glue and the booster. There are so many variables that I have decided to keep booster (Haifu regular yellow), glue (Butterfly Free Chack Pro II), blade (Franziska inner force ZLC) and FH rubber (H3 blue sponge) the same. My BH rubber has changed over time.