Spending two or three times on the Haibike is a bit of inefficiency with respect to funding.
What do we mean by efficiency here - range per battery capacity? That's really not a very useful thing, just limit your drive to zero power and your range is infinite.
A torque throttle gives greater control precision than a torque PAS. With throttle you can decide by the millisecond how much battery to use, and how hard to pedal, and what gear to be in. The amount of each is totally under your control in real time. This gives you the option to be efficient or to motor up the trail or road and give your legs a rest, moment by moment.
The torque multiplying drives don't have that fine control. The ratio between human power and battery power is not that easy to change on the fly, moment by moment. They are developing different control algorithms to try to automatically determine the right mixture, but like any automatic system the results vary and aren't right for every situation. It is kind of like the manual versus automatic transmission debate.
If you take a spill and injure your knee or ankle, which ebike will get you home? I've been in that position, and the throttle carried the day. PAS would have been a major failure.
So at the end of the ride, people need to respect other's choices. What works best for you is what works best for you. You should be able to choose, and not have some law (like the ones in California which require PAS over 20 mph) determine which you should use. Torque PAS gives your thumb a nice rest, but it is expensive and complicated to build into the bike. Torque throttles are much cheaper, simpler and more reliable to implement in the motor controller. But what we have mostly is PWM throttle which is not the best throttle control. The best system would have all or most of the options available and let the rider decide what to use. Limiting the rider's choices is taking away freedom. Why would someone want to do that? Reducing freedom of choice is not the American way.