Well, and don't take this the wrong way, but each route is really just a different set of happenings rather than another story, its a staple of the VN medium to retrace the story from multiple angles. Fate/zero does it another way, with the multiple protagonists showing multiple viewpoints at once, but even then, there must be sacrifices for time.
Anyway, there are plenty of hints on things hiding under the surface, so smart and observant readers should be able to pick up various things. Sakura takes somewhat of a backseat on Fate and UBW, but at the same time, there are various hints about her and her personality that go beyond just being the girl next door, its why I liked her in the first place. Like her relationship with Rin and the foreshadowings of it are shown, her relationship with Shirou and Taiga, and honestly, if you thought she was a regular girl, you were kind of delusional, there were hints and things everywhere.
For example:
I dunno, I just find that people don't pay enough attention to the subtle things put into this story. It is supposed to be enjoyed slowly and digested like a novel, because that is what it is. And there is a lot to digest.
@Thryfe