Disclaimer: These are observations, not 'polished' thoughts. Feel free to chime in with your thoughts to sharpen the discussion below.
One of the things that I mention to those who wonder about the importance of studying the Greek text as opposed to just relying on whatever English version(s) of the text they happen to read and study is the fact that they will often miss the little things, namely, the author's style, use of alliteration, and other nuances that make their composition a thing of beauty.
I began keeping a notebook yesterday of Romans, and I am following the outline that the NA-27 provides. So, in Romans 1.1-7, Paul's salutation, to the church at Rome, a church he had yet to meet, Paul claims that he was "set apart" (ἀφορίζω) for the gospel, which is ultimately centered on Jesus who is Messiah (1.1). The term ἀφορίζω is used in the context of holiness, much like Leviticus 20.26 (LXX) where God speaks to Israel, saying: "And you shall be holy to me; because I the Lord your God am holy, who separated (ὁ ἀφορίσας) you from all nations, to be mine." This term may also be related to what Paul says in Gal 1.15-16: "But when God, who had set me apart (ὁ ἀφορίσας) before I was born and called me through his grace, was pleased to reveal his Son to me, so that I might proclaim him among the Gentiles, I did not confer with any human being..." (NRSV). Paul's reference of his call in Galatians is an echo of God's address to Jeremiah where the prophet is told in part (along with the reference to the mother's womb) that"...I appointed (ἡγίακά) you a prophet to the nations" (Jer 1.5 LXX). The idea in either case is to be set apart by God for his special purposes.
Moving on to what Paul says concerning Jesus in Rom 1.3, Jesus is first, from the line of David, fulfilling his messianic requirements, and second he was "appointed" (ὁρισθέντος) the Son of God due to his resurrection from the dead. As Jewett states the verb means "install" here and should be viewed in light of the royal decree language of Ps 2.7 (Romans, 104). What I am interested in here, and the reason for the post itself, is the similarity in the language Paul uses to characterize his function as apostle, namely being set apart (ἀφωρισμένος) and Jesus' having been appointed or installed (ὁρισθέντος) as Son of God. In the few commentaries I have looked at thus far (Moo, Dunn, Jewett), no one has mentioned the similarity of these participles describing both Paul's call and Jesus' status. I'm wondering then, especially, phonetically, is Paul connecting his status with Jesus' and in what way?
If nothing else, Paul seems very purposeful in choosing these two participles, and reading this in the Greek gives us a glimpse of his genius that English translations simply miss.