I am usually in the 1984 Campaign. The mission files rarely have a fixed-wing or more than one helo. Looking at the immediate location of each mission and whether it is close to land, I added one of either. Being wartime, I think there would be increased air patrolling.
I tested it out with a Virginia and found that I need to keep a little more distance from the red task force which raises the difficulty and I assume that it will have a touch more "reality".
Instead of starting at 10k yards and being a "gunslinger", I have to start a bit farther out, fire torpedoes at max depth and range, do more sonar analysis, and get away from my launching point without alerting air and/or sea escorts. I do pay more attention to the mission screen and the weather and what my bearing is to the initial contact.
I understand the cheating techniques via the camera, but I avoid it. I found that I turn up the volume on my headphones and keep my screen on my sub more in order to listen for helos/fixed-wing aircraft at my sub's location. I can't just have my camera following my torpedoes all the time. It seems my listening is associated with where my camera is and staying with my own sub lets me hear when aircraft are overhead.
All-in-all, I am finding that I can't do other things while in a mission. It is a bit more immersive. Just finding that an extra helo or IL-38 keeps me on my toes.
