Floyd Toole talks about the "circle of confusion" that gets in the way of us knowing how to reproduce accurately what is on recordings. Dealers, too, can create another "circle of confusion" as they introduce additional uncontrolled/undefinable environmental factors in demonstrations, along with their own biases, implied or expressed. Finding a really fair dealer/demo is almost impossible unless you have an established and honest relationship with the dealer. I achieved that with 1-2 dealers before I began reviewing. It has become easier for me now but still not something to be presumed. Home demos are hard to arrange but they are important when we are spending relatively large sums of money and hoping for long-term enjoyment. It is probably worth paying for it, within reason.
What I can say is that I have had the wonderful opportunity to have heard most of the mentioned speakers, many side-by-side, in my home and those of friends. That allows me to be more certain about my choices and, although many others might have made other choices after such experiences, there was usually a consensus among those present. Friends who share an interest in audio can be invaluable.