the stake has to command a certain level of real world legitimacy and confidence for the voting behavior to be indicative of anything.
Smart traders paper trade their systems first, and then find that reality behaves differently. This is why large quant funds do back-testing first and then forward-testing with small allocations before scaling to meaningful size.
I go back and forth on this a lot. I think test nets are important, and SMTs will give an opportunity to test a lot of things. On the other hand, the most important impacts will only occur if the change happens universally across Steem instead of being opt-in.
Long-term, I don't think it all matters that much. SP holding will be about RC's instead of vote value, and most of the value distribution will be SMT's within communities. We do have to actually survive to the long-term.
While I responded negatively to your other comment about the tax, I think you are correct about the overall impact (and need) for these economic changes.