Speaker shootout question -- do you position the same or differently, depending?

"Optimally," one would position each speaker at its "optimal" location (quotation marks because optimality will always be a compromise of one sort or another), and have only that speaker in the room. Then live with that speaker for a week or more before switching. BUT: this precludes any rapid A/B or A/B/X testing.

What I've done (and I've done this a lot; it's fun!) is to position two sets speakers of similar type (and so, similar placement needs) next to one another, and switch back and forth by switching the cables; if I could do this with a remote from the sweet spot, I would. This gives me a sense of which speaker I prefer. THEN I set that speaker up "optimally" for a longer listen. If I'm still uncertain of my preference, I do the same with the competitor.

this is a really good thread to have alive and running on this board

should be one going all the time, as many if not most relative newbies come here focusing too much on the equipment, rather than how the equipment interacts with their room

So true, one need to have considered all aspects of the room when purchasing equipment. Selection of room drives selection of speakers, which drive selection of amplification,  .....

In my experience different speakers with behave quite differently depending on placement to boundaries and distance to listing position (reflection points, nodes, etc.)  The position of the drivers in the cabinet will give a wildly different presentation, as will the width and depth of the cabinets. 

If you don't have a symmetrical space -5, if  you don't have the ability to move the speakers around -3, add a great amp to this not optimal set +2, new expensive cables +1, etc. Obviously this isn't a scientific rating but without the first two, the (everything matters) approach with be skewed as well. Amps and cables matter more if you have the first two.

Do the best you can and have fun +10. 

IMO you're going about it in a sensible manner, listening and measuring.