[asid61]

While CoF is pretty important, I would argue that most teams can simply swap out their tread for blue nitrile or another high-CoF tread to get good results.
Drive efficiency is pretty variable, but it's almost negligible. A spur gear gearbox will have around 94% efficiency, so it really comes down to chain vs. belt drive. Even with that, the difference is less than 10%.
Drivetrain efficiency is extremely hard to calculate accurately anyway because of manufacturing tolerances.
Of course, this is not something that can be taken to heart, but for reference purposes it seems to do the job pretty well.