Thanks for the various comments. A couple more observations, if I may. As far as I'm concerned, when it comes to engineering, if it doesn't contradict the laws of physics, anything is possible. Secondly, when it comes to measurements, there are issues with aggregation. For example, differences in measured performance at component level can get buried when the aggregate performance of a device is measured. Thirdly, multi-variable dynamic phenomena are the hardest to model. Formula cars provide a good example of the latter. A team like Mercedes can go from having a dominant car to one which is marginally competitive in the space of one season. That's notwithstanding having an army of the best engineers and simulation and measurement tools. There is plenty of snake oil, mostly at the margins, of the hi fi industry. But there is also a huge amount of effort by honest, well motivated engineers attempting to advance the state of the art. Personally, I think that should be respected and given credit.