I recently went through most of the Biff tutorial but found it seemed to be missing some parts later on that had me scratching my head. It was otherwise a very enjoyable experience and Biff seems like a great way to get a "batteries included" starting point for web (similar to something like Rails or Django, though maybe not as comprehensive as either of those).
I'll see if I can go back and figure out where I lost track of things. I believe it was right around when making the message entry box functional. I ended up having to dig into the repo to see what I was missing.
Good to know--I'll do another run through the tutorial sometime and see if I notice anything. I know there are a couple things I need to update in the example repo at least.