On evaluating speakers?

Won't work. The microphone you use and how you place it is more important than the recorder. In the end all you'll really be doing is recording the speaker's interaction with the room.

It could be useful if you only used it in one room and varied the speakers (or other equipment).

Maybe I wasn't clear in my opening statement. I meant; to bring the recorder when auditioning speakers and using it as a source. This way the source is always the same and there is no variable there.

I have always had a problem with demos at 'the dealers'. Many many speakers at 'the dealers' have far to few hrs. on them.---Case in point, my new Sophia 2's required at least 6 month's at near 24/7---not they sounded like they needed all this time---they just got better and better over this time. I would imagine a listener at month # 1 might have a different opinion than a listener at month #6;??
Then we have the room,already mentioned.---The unfamiliarity of everything else being used. That includes the components /cables / power cords / speaker wire/ bases/ they all matter and contribute.--(Oh, and are all the wires in this demo broken in ?)
I would guess many dealers run their stuff in and out the door pretty fast.

Then why not just take a well recorded CD, DVD-A or SACD?