Well, I only speak with knowledge from the first 3 novels + Drama CD, but for the most part the series uses mysteries as the main driving force for the plot. That being said, the actual focus goes to the characters relationships and developments, so it's not going to let the mystery hog the entire story, but it'll be what gets the plot going.
I'd personally recommend that you watch each story arc instead of watching it weekly (which is what I'm thinking on doing depending on how the arc after next plays out).
Oh, and I love how you switched your avatar to Riza's :3
Question about Gosick. Is it just mystery after mystery, or do we see some different takes in the story eventually? I was thinking about putting it on hold, though if it changes down the line then i'll stick with watching it weekly.