Who positions their speakers straight ahead (zero tow in) and why.

@unreceivedogma I'd call that a moderate sized room.

Some speakers have tweeters with lobes that make the best listening when the speaker isn't pointed directly at you. Every speaker is different...

I can't immediately which ones, but there are speakers on the market with rising high frequencies, that are too bright when toed in, but sound great when toed out. 

@simonmoon With such speakers, to avoid side wall reflections which contribute to harshness, the simple solution is to toe-in the speaker so much the tweeters cross in front of the listening position.

In both cases I ended up with tweeters on the inside and zero toe in. I like the more immersive soundstage I get with zero toe in. I sacrifice a little of the lock in for the center image.

This can work fine with some speakers if there's no side walls. Side walls cause early reflections which are interpreted by the ear as harshness. If the reflection is long (+10ms) then the ear can interpret the reflection as echo location information which can make the sound stage image more palpable.

So in a smaller room where the speakers are near walls you'll want to toe in to reduce side wall reflections- that will make the system more relaxed. If this makes the tweeter too bright, you might have to toe in more so the speakers 'cross' in front of you rather than at the listening position.