I have found that with horn speakers such as Avantgarde that are very directional, substantial toe-in isa necessary if imaging is important. In fact, I've found the projected line of fire from horns should cross over somewhere between a foot or two in front of the listener to a foot behind - I prefer the former. I wouldn't care to suggest this has anything to do with reflections because in my present room (roughly semi-circular) and to a lesser extent my previous one (5-sided) the reflection issue is far from what may happen in most rooms. However, for best imaging, horns seem to generally be best pointing at the listener.
