@geoffkait , "I would be remiss if I didn’t say that there’s an infinite number of speaker locations for a given room, so obviously the ye olde trial and error method can only get you so far. You can NEVER find the absolute best locations that way."
You make a good point for most people. Although this may sound controversial, ONE AND ONLY ONE best location to site the loudspeakers exists in a given room for a system. That doesn't mean there's only one single point in the room, as altering components changes that position. It works exactly like focusing a lens. When you find it, the sonic level of the system jumps to a point otherwise unreachable. Just like a lens, it's immediately, obviously, and infinitely more right than anything else. It transcends so many of the dollars folks spend on supposedly better components. This doesn’t normally work for most people, as the complexities of life gets in the way. So unfortunately, they don’t even come close to realizing the capabilities of the system they already have