Here are some of the changes I would like to see to the GVs.
1. The ability to start or stop from the turret. Currently we can stear from the turret(top mount, pintle) but to stop requires going into the drivers compartment. The ability to stop one track, accellerate the other to turn would make the manueverbilty more realistic. Most of us have rudder pedals, with brakes, joysticks and throttles. Make use of them. This would move the player more into the role of tank commander instead of driver, gunner, commander. Some tanks such as the Panther had the ability to turn on its axis. Not all WW2 tanks did.
2. Damage model. The Flak wagon damage model is way out of wack. 3 or more hits to kill a Flak at a point blank range, yet a Panzer IV is out with one hit? Aircraft versus tank. This in itself may be realistic if you don't consider tank vs tank. Tanks vs tank will often result in a ping, ricochet, or minor damage yet a cannon firing aircraft can take out a tank in one pass? And P51s and other MG equipped aircraft can take out tanks?
3. New models
a. Panther,JS1, Grant, Cromwell, Crusader.
b. Tank destroyers; Hetzer, JgPzwIV, Nashorn, M 10, M36, SU7(?)
c. Moble artillery. Hummel, M8
4. More cities, strategic points to attack and defend.
5. More choice in spawns to reduce spawn camping. Or spawns that can't be camped.
6. Less interference from aircraft so we can have better GV battles.
7. Spotter aircraft such as the Storch.
There are a lot of other ideas out there.