BLS 85-90 covers how to provide for the congregation or assembly. Remember that though it seems these terms are used interchangeably, assembly is generally used for the inclusion of ministers and congreegation both. First up, the US bishops emphasize visibility:
§ 85 § The location set aside for the people will convey their role within the liturgical assembly.(GIRM 294) The members of the congregation should be able to see the ministers at the altar, the ambo, and the chair.
They do not mention the visibility of the congregation by the ministers, though. I recently heard a priest remark about how important that is for him, to be able to see the faces of the people while he preaches.
§ 86 § Since the liturgy requires various postures and movements, the space and furniture for the congregation should accommodate them well.(GIRM 311) Styles of benches, pews, or chairs can be found that comfortably accommodate the human form. Kneelers or kneeling cushions should also be provided so that the whole congregation can easily kneel when the liturgy calls for it. Parishes will want to choose a seating arrangement that calls the congregation to active participation and that avoids any semblance of a theater or an arena. It is also important that the seating plan provide spaces for an unimpeded view of the sanctuary by people in wheelchairs or with walkers. Experience indicates that space in the front or at the sides of the church is better than in the rear where a standing congregation obscures the view of those seated in wheelchairs at the back of the church.
This is good, but there is a thin line between traditional set-ups and theater in terms of reinforcing the notion of audience and performers. It’s one reason why I think worship with antiphonal seating is optimal, once those unfamiliar with it work through any unease. Also laudable is the concern for those with mobility issues, and providing for them in places other than the last row.
All texts from Built of Living Stones are copyright © 2000, United States Conference of Catholic Bishops, Inc. All rights reserved. Used with permission.
Catholic Sensibility 
There is one ergonomic problem that must be kept in mind with antiphonal seating: scale. That is, if the opposing lines of people are too long, such that sight lines involve people having to hold their necks at too great an angle (and it can be surprising how low that degree is for many people), then they will just tune out. I find antiphonal seating works best with shorter lines (in chapels or across transepts or Greek-cross planned spances, as it were), but *not* along long naves. Been there, done that, got the T-shirt replete with angry complaints.
Also, the placement of communion stations and procession lines needs to be considered vis-a-vis the placement of wheelchairs and those who assist those in wheelchairs. Too often, I find there is negligible consideration given to this problem.