Just an idea, i don't think spiral has something like this, but correct me (politely) if im wrong.
It'd be nice to get an alert or mail of some sort of a new reply on a thread you've been talking on. Alerts that can be enabled or disabled at the account holders leisure.
It's a bit difficult to keep up with which threads you've been talking on if you have multiple conversations going on, or they're in different sections; without having a lot of tabs open, or writing down the nodes etc etc