Wi-fi basically works across the board. System76 cares about fan curves and other mechanical/electrical details. Battery life is easy to call out, but I’d say that the work being done now is more nuanced.
I think battery life is one area vertical integration really helps. If all the hardware and firmware don't play nice, sleep and other power savings doesn't work right (at least in my experience). You'll have one rogue device preventing the machine from or some hardware missing software daemon power management config.
