Tried the first 2-3 missions of the campaign. I have to say, it is honestly pretty bad. And ArmA's clunkiness still pulls you out of any immersion that can be had.
Missions feel very much like ArmA 2's campaign, which were dull. ArmA 1's missions were actually rather nice. Large scale, lots of units, and more sand box like. This is small scale stuff, and are often you following AI around as they hopelessly navigate through the forest at a snails pace.
Switching between sight types is still a major pain, and the quick swapping of magnification to non-magnification is still disorienting (they didn't fix this from ArmA 1/2).
The interface is still awful. I honestly can't tell what type of grenades I have selected when using a grenade launcher while having hand grenades selected. It simply labels "white smoke", but when shooting it is an HE grenade.
Reloading the grenade launcher is a pain, as the animations are off. Hands clipping, pushing forward on an invisible object. While it does this, it points your view into the sky, and then back down again a full second later. Very disorienting, and if you compensate during the reload process the view will point at your feet when you're done. In short, using the grenade launcher in combat is a terrible idea due to the awkward implementation of it.
Placing and interacting with mines still uses the terrible scroll wheel interface. Same with entering vehicles. So entering a vehicle is still a chore, as you're not sure if you're going to enter it, or switch weapons, or open its inventory system when you press enter. To get inside of a vehicle you also must look at a very particular part of it. Getting inside of a truck should not be so difficult.
To top it off, enemies can take 5-6 shots to the chest while you die in 2-3.
Overall I am finding the campaign to be just as underwhelming as previous titles. The voice acting is still shockingly bad and the horrible, half finished content and implementation issues make the game a chore to play. Its like they decided to improve the game, but then gave up halfway through development and decided to shovel more of the same dirt onto the shelves and charge full price for it. At $33, with the current state of the game, I feel ripped off. They make Eagle Dynamics look extremely competent and quick with making significant changes (which, they actually do).
I am even more eagerly awaiting Ground Branch's kickstarter. I'll probably uninstall this game to free up SSD space. ~ 17 hours in Steam so far, and most of that was messing around placing units and ammo boxes.