The Kemper and Fractal units have an always on-tuner which can always be seen on any screen. It would be great to have this on the Quad Cortex. Also the ability to use the regular tuner while passing the audio (I believe it mutes the signal currently).
Also it would be nice to have the option to instantly access the tuner rather then a long press. That way it would be a mute switch as well, which the QC needs anyway.