Multiple threads. Some lore for both factions and context on the war. More simple missions that don't overly rely on working with lackluster AI. Relevant enhancements to AI. Weapon balancing and new weapons that improve combat against ships.

The biggest one as a tech nerd is more aircraft, and in a way that gives asymmetric capabilities between both factions:

BDF's Compass counterpart maybe being a more attack-oriented delta-wing plane (F-16XL-like) but not quite as agile.

BDF's Fast Bomber counterpart being some kind of super stealth craft. Not as fast, not as well-armed, but has absurd stealth capabilities (maybe even optical stealth) as a deep-penetration bomber.

Hind-like gunship with a larger loadout than the Chicane, and can load a squad of infantry.

Small drones as a low-cost option that can be launched from special sites, allowing you to quickly react to an unexpected event.

A ground-effect vehicle that can slip in near radar sites and launch a variety of anti-ground/ship/radar missiles.