Since I respond to visual items best, I would vote for a digital meter for selected parameters instead of a number (FE, LOD, TPS, GPH).
To take the work out of it, the device would upload to a PC (wireless, bluetooth, USB, whichever). The program would interpret the highest cruise FE and the parameters present during that run (timing, IAT, LOD, speed bands).
I'd also vote for previous suggestions of a HUD, and wind speed / direction.
If we're dreaming here: it could also program fuel maps and shift autos manually.
RH77