I really like this idea, in theory. But putting it into practice seems to raise a little problem. I don't know how to isolate speakers from the rest of my system in order to determine which speakers are "the ones" for me.
Some issues can obviously be addressed: like matching the size of speaker to size of room, or the basic speaker type (whether it be a line source or single driver or horn or whatever). But even within fairly narrowly described sets of speakers (e.g. two way stand mounted monitors with sensitivity around 90dB), there is a lot of variation. Moreover, each speaker will sound differently on different systems and in different rooms. Unless I have the opportunity to hear a wide range of these speakers with a wide range of components in my own listening space, I have no hope of knowing which speaker is the right one for me.
Ultimately, I think we're all faced with the same reality. Given the system currently owned, comprised of many elements, each of us gathers information from professional reviewers, trusted enthusiasts and personal experimentation, and chooses upgrades deemed to offer a high probability of improving the system at a reasonable price. This may or may not involve changing speakers at any given time.
My personal approach at the moment specifically avoids dealing with my speakers. I feel I've found a pair of speakers that work reasonably well for me. I don't believe they are the best I can find, or are likely to be the speakers I will use for the rest of my life. But they give me a basic presentation that I enjoy, and in my mind I am committed to sticking with this type of speaker for some time (single driver with relatively high efficiency).
Now,my efforts are focused on finding high quality, built-to-last, reasonably priced amplification which will mate well with this type of speaker. Seriously, I want to find amplification with which I can live for many, many years and never worry about again. That will allow me to think about only two things: a digital source (which seems to be a world that's evolving so rapidly, I couldn't imagine committing to anything), and speakers (within the general type that I have already chosen). I take this approach now with the realization that my ultimate speaker choice will be influenced, partly, by the choices of amplification I make today.
Chad