I only have short term personal experience currently, as owning a Flowerhorn has only been a 2 week endeavor at this point, but I did research both on and off the forum and am happy with the NLS Float - Large Pellet I landed on. The “Best pellet for flowerhorn” thread on this forum has a wealth of knowledge on this topic.
I found some owner concerns about Flowerhorn Cichlid targeted products that had more protein than was necessary but I’m sure more experienced owners than I will weigh in.
For what it’s worth, Sheriff gives the NLS pellets two fins up for taste when I feed it!