Augustine's understanding can, I think, be fruitfully used in another context: the Iconoclastic Controversy. St John of Damascus uses a technical distinction between latreia and proskynesis: adoration and veneration, respectively. (It is important here to note that both actions fall into the larger category of what we call "worship." The difficulty with this is that our contemporary use of "worship" is closer to that of adoration; one has to only go back to 1611 to see that it wasn't that long ago we had a broader understanding. Moses worships Jethro, and so on. Or look to the BCP Rite of Marriage: "with my body do I thee worship."). While God alone is worthy of adoration, the saints, the Theotokos, and holy objects are to be venerated. St John faced stern opposition from his fellow coreligionists, as they understood veneration to be a form of idolatry. However, St John (and St Theodore the Studitie after him) said, in effect, that one cannot honor the saints who crushed the idols by making them into idols -- in other words, veneration of the saints was not the same as adoration of them. Rather, if one was to properly venerate, it could only be done in the context of adoring the Triune God.
The West, even though it technically adopted the distinctions as proper theological method, long struggled with them -- the Carolingian Franks viewed the use of religious art in a distinctly different light than the Byzantine Romans. This came to a head, of course, in the Third Iconoclast Controversy of the Reformation (and, yes, not all Reformers were so inclined -- Luther's view seems to me to be a republication of the Carolingian understanding). However, if we bring Augustine and Damascene together, we will find that they are speaking the same language.
Augustine's "enjoyment" of God corresponds almost perfectly with St John's "adoration." God is the only One worthy of such actions, which involve complete love and devotion offered to Him. "Use" then is analogous to "veneration." This provides the clarifiying paradigm that we need to fully make sure our veneration (of one another, the saints, or the Theotokos) does not lapse into idolatry by adoring that which is not God by nature. If we love God properly, that is as God, we will love His saints, His mother, and all other things in their proper place. If our adoration is of Father, Son, and Spirit, then we actually can honor and venerate all other things in freedom and safety: our love of God, poured into our hearts by the Spirit Himself, guides us in this.
This, for us Protestants, is very unsettling language. We are used to thinking that, even after the coming of Christ we are under the rule of the Law, instead of the freedom of the Spirit. Certainly, we've seen many abuses by this who have claimed the Spirit -- but abuse does not negate the possibility of proper use. If we actually have the Spirit, though, we have freedom to move and breathe, all the while never forgetting the Law we do live under: the Law of Christ, that we shall love one another and so fulfill the Law.
How, though, do we know we are adoring God properly, so that we might venerate with order? It should give us pause to consider that this is the driving question behind all the various debates that led to the Ecumenical Councils. Is Jesus God? (Nicaea I) Is the Holy Spirit God? (Constantinople I) Is Mary the Mother of God, or just a man associated strongly with God? (Ephesus) Does the human flesh of Christ share in the properties of the divine Word? (Chalcedon) Is the humanity of Christ true and full humanity, complete with distinct will and activity? (5th and 6th Councils) Does the divine nature deify created matter? (Nicaea II)
It is Nicaea II, which declared iconoclasm to be of non-apostolic origin, that brings all this together. If we properly venerate that which is venerable, through such we adore God. Since we are creatures of matter, it is only through the mediation of matter that we can love God. Can God so use matter in a way that opens up true and proper worship of Him? If we confess the Incarnation in any sort of orthodox way, we must answer 'yes.' The infinite God truly became finite man (without ceasing to be either true God or true man), so that we finite men might share in His infinite Life (or, God became man that man might become gods -- St Athanasius in On the Incarnation). If that is the case, then can God share Himself through other parts of creation? If so, then when we properly venerate where He chooses to share His grace (through bread and wine, through His saints, etc.), we are adoring Him through their mediation.
Augustine's proper ordering of loves, then, works in two directions: if we love God rightly, we can rightly love all lovely things. If, as well, we love all lovely things in the way they are to be loved, then through them we can adore God.