I've seen some conductors insist on putting the 2nd violins to the right of the conductor (facing 1st violins).
Personally, I am firmly against this practice.
The conductor is the only one who will actually benefit from this seating as he's the only one who is in an ideal position.
The 2nd violins are all facing INTO the orchestra from that vantage point, thus reducing the amount of sound they direct to the audience.
As an audience member, I have yet to actually hear any sort of advantage to antiphonal seating unless it is greatly exaggerated, for example, placing individual brass players in balconies to the right and left of the stage.
Instruments actually ON the stage are too close for the ear to really differentiate the stereophony.
if you want to see an extreme version of this, look up the live performance of Steve Reich's "Desert Music". The entire ensemble is divided into 3 equal-sized groups, one left, one centre, and one right. The idea is great, but again, the only person who truly benefits from the placement is the conductor. Audience members will not hear distinct groups, unless they are sitting in the very first row.
