Can you explain what a subjective opinion of a device that does exactly the same thing as another device would tell us? I mean it's like a food critic saying he can tell that food cooked on one stove tastes better than food cooked on another stove that in any objective way is the same...but he can only make that subjective confirmation if he knows the food was cooked on the one stove and not the other.
Well for starters, why start with a single sample?
To build on your example, suppose:
100 food critics tried a particular dish cooked on stove A and stove B.
90 of those food critics reported that the food cooked on stove A had a burnt flavor to it.
But when you measured the temperature of each stove using a precision thermocouple, they were identical to within 0.001C
It would be tempting for many folks here to stop and say, "well the stoves are identical, the precision thermometer tests prove it, and the food critics are fools."
But a natural/research scientist would say, no, maybe there's some merit to the fact that in our sample, 90% of food critics reported the same subjective concern about food cooked on Stove A. And a natural/research scientists would ask WHY. And would generate a hypothesis that explains all observations (i.e. both the subjective food critic responses AND the thermocouple readings) - and then would test that hypothesis.
That's the difference.