disagree, because I've actually SEEN it working.
A guarder AK at 310fps can outrange a poorly tuned VSR-10 at 470fps.
My G3SG-1 at 360fps outranges an HFC VSR-10 at 470fps
My HFC beretta at 290fps outranges any stock CA, G&P and TM AEG
My UMP shooting 280fps with nothing more than a hopup rubber and a cylinder set outranges a fully upgraded systema AEG.
Hopup rubbers don't make up for fault in the system, they just help the gun get more range. If you don't have proper compression, the gun can't recenter the BB in the barrel after it hits the hopup rubber and your range suffers greatly.
It's not about FPS, it's about COMPRESSION, they're two entirely different concepts. The stability of your BB on it's way out the gun as opposed to the velocity of the BB. And it's the whole reason why a fully upgraded sniper rifle will always out shoot a fully upgraded AEG. Better compression wins every time.