After a full day of prep, we sat down and went through only the first layer of what I had ready. Which is exciting! Because now next time I've already got a bunch of stuff ready, and I can just work on cleaning it up and making it a little deeper, rather than needing to come up with lots and lots of completely new encounter concepts.
Home base has been established. Plots were thickened and mysteries exposed. Also, following the Gumshoe model / Alexandrian method, I didn't make the PCs roll to find clues, I just had them find everything that was there to be found by looking. This works REALLY WELL. I recommend it.