Also it would be better when you zoom to a selected unit that the default camera position be near ground level, behind the unit but level with the ground so that you are looking past the unit at the horizon instead of a position above and behind the unit looking down and seeing nothing but the unit and the ground.
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I would like that too.
What I generally end up doing is once I hit the camera button or Q hot key to go to a selected unit is hit the Q hot key again and then the L hot key(I changed my hot key for leveling the camera to the L hot key)This puts the camera level and slightly behind the commander of that unit.
Also I get some lag with the camera in the beginning of a battle but not so much later in the battle(I don't know why)I also get a few occasional camera hiccups every now and then during the course of the battle,this can be somewhat annoying but not extremely since it doesn't happen often.
My camera speed is usually around 7-8 and I use the arrow buttons and mouse scroll to manipulate the camera.I very rarely manipulate the camera with the screen perimeter control.