So excited for the Career mode! The announcement of it was pretty much what sold me on BoS. I loved Rise of Flight's Career mode for how well-made it was. Each pilot had a name; the structure of getting a mission, taking off from your base to do the mission and encountering enemy recon, fighters, and bombers, and going back to your base; getting awards and promotions ... it's a great way to add flavor to the game, especially with all the units being present and a lot of them having their skins and history shown in-game.
Kuban's aircraft and scenery are looking great, so I'll probably jump into it at some point.
By the way, I read that the Career mode is planned to go into a beta in October. If so, will that only be for BoK or will it include BoS and BoM? Either way, it'll be a long wait for me. But worth it, I'm sure.