yea..i agree, I was just thinking the same thing.
There is no hi rpm dive sound or engine revving with
relationship to airspeed.
Also noticed the cfs and cfs2 seem to use multi stage samples
for thier engines.
i.e. idle and hi rpm are 2 seperate sound samples. Not sure
if that is applicable, but is difficult to get a killer idle sound
AND a great full throttle sound with one sample. Have to split the difference.