Ok, so to start, fantastic modeling, texturing and FM! Great work.
Now the sounds, which are great, just need tweaking. If your going to simulate noise cancelling headsets, then the ground roll noise should be reduced accordingly. The ground roll is really loud, even without the headphones it takes away from the experience.
On a side note, I get realism, but that twichy brake castoring steering in xplane (yes thats XP not you guys) could be dampened or at least an option to turn off castoring steering.