Update: I originally wrote this series of posts in 2015 and since then I have changed my view. I’ve decided to keep the posts live, but wish to add that caveat at the outset.
I have suggested that the economic revelation is a truthful, if partial, representation of the Triune God in eternity. However, Giles writes that the economic Trinity, ‘cannot be limited to what is revealed in the incarnation […] The revelation to human beings on earth of the Father, Son, and Spirit […] is given in Scripture in its totality, not just in the Synoptic Gospels.’
I agree, but wonder how this observation advances Giles’ argument. First, a good deal of the material used in the discussion comes, not from the Synoptics, but from the Gospel of John in which the Father-Son terminology is exceedingly prominent. Keener, an Egalitarian with respect to gender roles, makes a strong exegetical case for the eternal obedience of the Son from John’s Gospel.
Second, Giles doesn’t indicate which texts he has in mind. In Grudem’s, Ware’s and Horrell’s treatments of the Trinity, they quote supporting material from across Scripture demonstrating the Father-Son authority-obedience relationship in election and creation, sending and incarnation, and finally in exaltation and new creation. Much of this textual evidence is neglected by non-Subordinationists.
Three key passages from the Epistles feature heavily in the discussion. 1 Corinthians 11:3 has caused much debate surrounding the meaning of kephalē (head/source) and the consequent implications for gender roles, which we cannot hope to unravel here.
Philippians 2:5-7 speaks of the kenosis of the Son, which Bilezikian stresses was neither a demotion to accomplish a job no one else wanted to touch, nor an involuntary act forced upon him, but rather his self-humiliation; the giving up of equal authority with the Father. However the text says nothing about Christ giving up equal authority with the Father and seems rather to be speaking about equality in glory and honour, which Christ surrendered at the incarnation, and had restored to him by the Father in v9. Neither does the text suggest that this was the first occurrence of Christ’s obedience to the Father, but rather ‘it focuses on what was new: obedience as a human being, and obedience to the point of death.’ As Dahms puts it,
an eternal attitude is being exhibited in a particular act of humility and obedience […] Indeed it may be argued that there must be such an eternal attitude if we are to hold that the character of the Son never changes (cf. Heb 13:8).’ 
1 Corinthians 15:24-28 is another crucial text, which describes Christ ruling until every enemy is defeated (v25-26) then handing over the Kingdom to the Father (v24) so that the Father may be all in all (v28). The Father subjects all things to Christ with one exception; Himself (v27). The final, presumably eternal, scene has the Son being subject to the Father (v28). Non-Subordinationist treatments of this passage are largely unconvincing. Bilezikian sees this as an extension of the incarnation, saying
one more time the Son will be made subject to the Father so as to bring the work of redemption to a triumphant finale […] Any inference relative to an eternal state of subjection that would extend beyond this climactic fulfillment is not warranted by this text’ .
Giles tentatively cites Pannenberg’s view that ‘in the handing over of lordship from the Father to the Son, and in its handing back by the Son to the Father, we see mutuality in their relationship,’ but admits that ‘Pannenberg gives no exegetical basis for this claim.’ I have yet to be convinced by a non-Subordinationist reading of this text and agree with Keener that ‘in the end Christ himself will be plainly subordinated to the Father (15:28) in a more complete way than he is before that day (15:27), though he sits already at the Father’s right hand.’
 Giles, (2006) 264
 Ibid., p119
 See Keener (1999). Also Carson, (2000) p30-43
 See in particular Grudem, (1994); Ware (2005); Horrell (2004) p411
 See Grudem ‘The Meaning of Kephale (“Head”): A Response to Recent Studies’ in John Piper and Wayne Grudem (eds.), (1991) for lexicographical studies, and the relevant commentaries for further discussion. Especially Thistelton, Fee, Witherington and Keener
 Bilezikian, (1997) p59-62
 Grudem, (2004) p409
 Dahms, (1994) p362
 Bilezikian, (1997) p60
 Pannenberg, (1991) p313
 Giles, (2006) p115
 Keener, (1999) p48