Users, reactivity, partials, and it's fast.
Users are using CouchDB _users for storage and password/salt hashing/checking and passing to passport for cookies.
Reactivity is in-tact in it's infancy for the users_index view, updating and adding is wired for realtime changes to the view.
Partials are precompiled and available as Handlebars.partials['partial-name'] on the client side (this helps us with the reactive rendering).