Usually people don't look for improvements they look for Flaws, Loss of Stability, Broken features, and Lags........
You won't find any of that with this kernel so when people see their phone performing perfectly fine with no Loss of Features or Stability they question whether the Kernel has had any effect.....
I can guarantee you this kernel makes the improvements listed in the OP just compare it to the Stock kernel....... Camera Quality is better, Asphalt 6 or any other game's Audio doesn't sound choppy like it did with stock, and I have yet to see one Lag while using Power Kernel