There is a whole field of psycho-acoustics that covers what you can actually hear and sadly we are very emotional and subjective creatures. If you are feeling great or just exercised music will sound better. And if you expect something to sound better, your brain tends to reinforce that expectation. When you see a huge amplifier in big chunks of beautiful metal you expect it to sound better.
There have been debates for years about how much interconnects and speaker wire impact sound quality and people will argue until they are blue in the face that a set of thousand dollar interconnects sound better.
In case you are curious a friend of mine, Ethan Winer, an engineer spent over a year designing and creating a device called a null box that allows you compare audio signals traveling through wire by canceling them out so that you can only hear differences between them. Spoiler alert, there is none.
That's a lot to write just to say that at some point differences start to get very small to the point where you can't feel a difference. Given enough power at the wheel, the software driving a system becomes the most critical part. And how a DD system reacts to the information presented by software becomes the critical thing to see.
It might actually make sense to read/graph raw wheel position sensor data from different systems and see what they look like side by side to empirically see what they are doing differently. It might be good to see the control signal along with this to see how close it matched what it was being asked to do.
If we had a known good that reacted really well it might make sense to get a good FFB loop that was representative and to tweak the various driving software out there to see how close they could get the different systems to match that graph.
I would be interesting to see what really differentiates the systems. I suspect the overall power and driving software are the most important given decent sensors. Encoders are another thing I wonder about. How much resolution really matters. Past a certain point software should be able to compensate.
