Harland Sharp Rocker Arms

I have been looking at rocker arms ! I have been looking at Harland Sharp!! I noticed that they list a rocker arm for Trick Flow heads ! I also noticed that the rocker arms for the Trick Flow are a couple hundred bucks higher ! So what’s the difference between the Trick Flow rocker arm and the regular rocker arm ? It does say the Trick Flow rockers are heavy duty !! So maybe a heavier gauge aluminum, and stronger needle bearings ? Just wondering if anyone has actually looked at a side by side comparison ? And, if that is the only difference ?