I'd mostly want a mix of the two. A large, open map where you can play as an infantryman and customize loadout while also doing the same for your squad. You can choose to enter a car spread out on the battlefield. However, that's a lot to ask for a flash game, so I'll settle.
The enemy soldiers should have critical points like hear-shots and head-shots. It's a little off-putting if a shot in the foot does as much as a shot to the eye.