Everything changes the sound. I have the speakers about 90" apart, and I seem to have good stereo. If I move the speakers much further apart, I can hear the individual speakers more, and if I move them even further apart, within the limits of my room, I get a hole in the middle. If I move them a few inches closer together, it still sounds good. The toe-in seems to primarily affect the placement of instruments/voices, and in doing so, also seems to reduce the soundstage. I want the most accurate sound possible, and I don't want to merely rely on what sounds good to me, because I don't really know how it is supposed to sound, objectively. (I think that listening is a developed skill; otherwise, we wouldn't go through these processes, and everyone would be happy with whatever they had.) Notwithstanding, I prefer to have the location of voices and instruments easily identified rather than a "voice from above" (or somewhere). (Reminds me of the Wizard of Oz; they must have had terrible acoustics in there, because Dorothy et al were looking everywhere when they heard Oz's voice.) The placement of acoustic panels also affects the sound. I found that putting an additional panel on the ceiling between the speakers before the first reflection points brought the vocals out forward, notwithstanding the three panels on the ceiling that cover the reflection point. Also, my distance from the speakers affects the sound. When the speakers are further apart, I prefer to sit further away, although my room isn't very long. When the speakers are closer together, I find myself leaning forward. To me, that suggests that a lot of toe-in doesn't sound that good to me.
But, is there something specific about the SongTower design that indicates speaker placement without toe-in?