Over the past few days, I’ve jumped into the Mapzen/Tangram ecosystem. First impressions: somewhat steep learning curve to grasp YAML format, lighting options are pretty neat, very fast to render GeoJSON, documentation is good although asks a lot of the newbie reader, the provided Mapzen Vector Tile Service (mostly OSM) is awesome, and I bet shaders are cool, but I don’t understand them (yet).
My example is largely based off the Mapzen JS Walkthrough, with a few simple additional wrinkles. I draw parcel geometry and attribute data directly from Open Data Prince George. I take building data from the same source, remove OSM buildings from the scene, and draw/extrude 3D buildings based on the building height attribute.
Darren's Side Projects 
Hello from Mapzen!
We’re flattered that you chose to use Tangram and love the example you came up with. We also agree on your assessment that YAML has a steep learning curve and there’s a lot for a newbie to learn before being able to fully use Tangram On that note, we’re hard at work improving our documentation and tutorials. If you’re open to talk to us about your recent experience learning the language or tutorials/educational materials that could be helpful to you in the future, please reach out to us: irene@mapzen.com. We’d love to chat with you!