I enjoyed the confrontations in this chapter, though I suspect some other characters didn't. Matt's confrontation with Dudley was interesting, I hope it was educational for Dudley. The confrontations with Draco were about as expected, he's the child of his father's brainwashing and it looks like he'll have trouble growing beyond it, if he can. The meeting with Luna, esp. 'tween here and Matt was interesting; I take it she's got a somewhat earlier birthday in this fic so as to be in the same year as the others.
chuckle Matt and Harry both have obviously absorbed the attitudes of their American home with a less than high regard for self-proclaimed aristocracy. I don't think Draco expected quite that reception; I doubt he'll appreciate dealing with them for the next seven years.
All in all, a good story so far and I'm looking forward to seeing how things develop once they're at Hogwarts.