This is one of the more interesting and fascinating threads I have read.
I agree with Pyro's general statement that the vehicles are meant to be more complimentary in nature to the flight sim aspect.
Having said that, one of the most immersive experiences I've had so far here, is when I was part of an armored column push as a Panzer on an airfield.
We had Panzers and M16's, with an awesome fight for air-superiority going on above us.
Couple that with an enemy armored column rolling out to meet us and WOW!
Stopping to fire at the enemy ground units, then moving to avoid fire, calling in for air-support and watching enemy air come at us, then above all of that, the dogfights that took place to gain the air-superiority to keep the skies clear for the Jabo's and the armor was, again, totally immersive.
If the excellent suggestions were to be added regarding the icon idents, the immersion level would only increase.
So while this is a Flight Sim at heart, the vehicle aspect has added so many new possible dimensions in planning, strategy, and immersion.
I know this is a long post and I haven't added anything of suggestive value, but I just had to comment on the quality of the thread, and my own experience with the addition of the ground aspect.
Cobra out!