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

I have Magnepan 3.7i speakers.  I have experimented with many different degrees of toe in.  I have found for my room that having the tweeter ribbon on the inside and just a few degrees of toe in works for me.   The speakers disappear and have an expansive soundstage.  Huge width and depth.    When I oriented the speakers with the tweeter ribbon on the outside the center fill went to pot!  As with all things YMMV!

Anyone else here experimented with asymmetric speaker toe-in?

@bolong

Well, I am. My room is large but asymmetrical, so I thought it was worth trying. I am far from done, but at this point my left speaker crosses ~2 ft in front of my head while my right speaker crosses approx 1 ft behind my head. They’re about 15 ft away from the front wall. I would say this is the best they’ve sounded so far.

Sometimes getting goofy pays off. It's what I like about this hobby.

I've owned three pair of Vandersteens and believe Richard recommended straight ahead.  But he also recommended some distance from sidewalls which is addressed by others here.  

Some other speakers I've owned worked best  aimed just behind my head.

So another vote for "depends on  the design of the speaker and room set up".

I have Maggie 3.7i and regular 3.7s before that. In about 10 years, I’ve tried everything I could think of, and with these speakers, movements of 1/4 inch make quite a noticeable difference. I’ve ended up with the tweeters out and very little toe-in, about 1/2 inch, just a couple of degrees. They are on the long wall of a room that is 14x18 x 8 feet with wide doorways on each side of the Maggies. Audiophiles who visit comment on the wide, deep and tall soundstage with nearly pinpoint imaging. After 50 years in this hobby, I am a very happy man!