Upon replaying this route, now I realize why I love this route so much. It isn’t the sudden complexity and layers on characters (heck, Gilgamesh got more subtle characterization in his few scenes here than in most of his appearances in Fate and UBW), or the actual compelling plot, but the focus of the relationships. Yes, romance played a great part (more than UBW, but wasn’t the whole point of the story like Fate), but it touched family relationships (my favorite). The emphasis on the siblings bonds between Shirou and Illya, plus Rin and Sakura was a treat.
Family play a part as important as romance or ideals.