You can certainly argue whether or not you think ad orientem or versus populum better represents what it means to face Christ, it is a fool's errand and only admits the error of the modern liturgical to frame it as a choice between altar or people. If that is the choice, then I vote for none. No man of God worth his salt is facing the altar or the wall or east or liturgical east during the Divine Service. Our only posture is to toward Christ. And, while we are at it, this very dispute only confirms the important loss of the eschatalogical which, though present in words, seems to be absent from the hearts and minds of God's people and those who serve them from the altar.
To say we face Christ is to say we are looking toward His coming again in glory. It is an eschatalogical posture surely missing in an immanent Church. That is the source of our problems over posture and direction and that is what cries out to be resolved in the life and perspective of the Church. It would seem that the Revelation of St. John was placed in the canon precisely to disavow the Church of this error of focusing on those assembled or on the furniture of the chancel or on a wall of the church building. We are not looking toward any earthly direction but to the Christ who is to come. One may argue and play games over which side of the altar the celebrant stands but it is no game and no amusement that most of the celebrants and the people do not see the posture toward Christ in either point of view.
To the Protestants who worship the absence of God or His presence in their emotion and experience, we cry out, "Hey, over here. Christ is here!" and lift the host and the chalice. But this is no mere conflict of locations but of perspectives. The ancient Church was much more eschatalogical in its understanding and direction than we are. We have come to presume that God is not coming anytime soon so we are justified in turning the focus back onto us (our problems, wants, desires, and needs -- at least as we would define them). But He IS coming. That is the terrible problem that is resolved in the Eucharist. We see Him who is to come as the same compassionate and forgiving Lord who suffered and died for our sins and who won the victory over death by escaping the prison of the grave on the third day. It is not that we only see the Cross but that we see Christ through the cross and are thus prepared and focused on the Coming One with joy and relief. The absence of such holy joy and the lack of such anticipatory relief is a sure sign that what we see in the room is only the people and the altar -- not Christ the redeemer come to turn the redeemed heavenward so that they will see Him when He comes again.
The eastward-facing position of the celebrant in the old Mass was never intended as a celebration toward the holy of holies, nor can it be described as “facing the altar”. In fact it would be contrary to all theological reason, since the Lord is present in the Eucharistic gifts during the Mass in the same way as he is in the gifts of the tabernacle which come from the Mass. Thus, the Eucharist would be celebrated “from” the Host “to” the Host, which is plainly meaningless. There is only one inner direction of the Eucharist, namely, from Christ in the Holy Spirit to the Father. The only question is how this can be best expressed in liturgical form. Joseph Ratzinger in The Feast of Faith: Approaches to Theology of the Liturgy
Furthermore, the Eucharistic offering must also be about the Christ who offers us to the Father as well as our song of praise and thanksgiving or else we have missed it still. It is not simply about whether or not the Church offers Christ or re-offers Christ to the Father but who Christ is offering. He who has vanquished our sins with His suffering, cleansed us with His blood, clothed us with His righteousness, and raised us from the death of sin has not done so in order that we might look good here and now but that we might be prepared to stand before the Father. This is what I fear is sorely missing in the preaching and teaching and faith of those on both sides of the rail. We Lutherans are keen on talking about gottesdeinst as God serving us with Christ's gifts that flow from the cross and empty tomb but perhaps we have forgotten why He serves us. It is not for here and for now but for eternity, that we may be found holy and blameless when He comes in His glory. Heaven on earth in the liturgy is not a permanent location but always a tent of meeting in motion, moving ever closer to the completion, consummation, and culmination. If this is to be true in our lives, it must first be true about what happens at the altar.