Originally Posted by terenz
The 340-300 (assuming LA doesn't have -500s or -600s, or even -200s) is known for lacklustre takeoff performance (i.e., it is underpowered). The full load and relatively long range may account for the slow and hence less noticeable rate of climb.
Underpowered may be the wrong term. Suggest that the aircraft is poorly designed.
The 340 is designed to use minimal power for takeoff (less stress on the engines) so that it appears sluggish. Nothing wrong with the aircraft.