Certainly, but growth alone should never be the true measuring stick when evaluating the overall health (and longevity) of a fish. I can grow cichlids out like a hot damn on a diet of trout chow (which is high in both crude protein & crude fat) but I will also guarantee that same diet of trout chow will eventually lead to health complications such as fatty infiltration of the liver, heavy vacuolation, and necrosis of the liver, pancreas, and spleen. In a nutshell, a shortened lifespan.
And Frank, adding Vitachem isn't going to boost much of anything, if Hendre is already feeding a staple of decent quality pellets. It's not like adding vitamins is going to change the omega 3 to 6 ratio, or undo any of the other potential issues that can come with fish farmed in China. Tilapia is relatively cheap, and widely available, but IMO a far cry from pimping a fishes diet.