I've been doing a bit of whining recently, but the good bit for me is still the overall feeling of 'being there'.
It's hard for me to describe, but the overall atmospheric ambience of CoD when you're sitting in the cockpit is unequalled anywhere, including all the REX, VFR, GEX addons for FSX. For this reason, I always fly with the canopy open.
You look around at the sky, your wing, you lean out to check the colour of your exhaust flame, you check your gauges, then spot the enemy and dive to the attack.
Then you realise that shooting them down is difficult, as it must've been IRL, the rear gunner pops one in your engine and you have to crash land in the undulating landscape with its various types of highly detailed vegetation (although the tree issue is well known).
A couple of months ago, I said I could 'almost smell the air' and I stand by that view.
So in spite of my recent whining, I just can't leave it alone.