First, I tend to go with the minority reading, due to the smoothing which is often found in scribal errors.
Second, I think that if this was a performance piece, which I think it was, then the original audience wouldn’t know fully yet who Jesus was. Given that, we do not actually encounter someone or something calling Christ the Son of God until Mark 3. While the incipit declares that this is the beginning of the good news of Jesus, the words commonly translated as Son of God are themselves a variant reading, although one I would support given what I believe to be Mark’s sources. Regarding the rather dubious title, Son of God, we have not yet been introduced to Jesus as the Son of God, although admittedly, I see that term as one which neither Jesus nor his disciples (in Mark), never use, but only comes from demons (representatives of something, I would argue) and the Roman Centurion. Further, in Mark 1.21–28, the “demons” calls Jesus the Holy One of God. The term “holy one” was used numerous times in the Hebrew Scriptures to represent, notably, God (usually with the addition of “of Israel”), and to David (in the Psalms, especially the one which the Messiah-believers quoted to favor the Resurrection) and Aaron. One was King and one was High Priest. I do not take the use of “Holy One” to mean that Jesus is being called the Son of God by the Demons, but following his adoption and anointing in baptism (see Psalm 2 as well as the fact that Jesus can now heal lepers, Lev. 14.), Jesus is now both King and Priest, a recognition which is placed in the mouths of the so-called demons so as to propel the story along. I think that, as others have identified, that there is a connection between Mark and the Elisha narratives, and specifically, I think that the emotion of King Jesus is related to the emotion of King of Israel in 2 Kings 5.1-8.
Finally, I have to side with Metzger that Jesus’ emotion (perhaps better understood as indigent rather than angry) is connected with the ferocity of the warning which Jesus gave to the man regarding promulgation of the event. By the end of this pericope, Jesus is no longer able to go into any towns, and thus, we could see this hindering the Gospel. Granted, this gets away from textual issues somewhat, but I do think that given the connections between Mark and the Elisha narratives, the usual softening by later scribes, as well as the stern warning by Jesus, then I would have to go with the minority reading, which, admittedly, is my predilection.