I've been using and refining this for at least a week and really liking it. With this new preference, "Filterable Lists", when you type inside a list, instead of only navigating to the item that begins with that key-sequence, it will exclude the non-matching items altogether, and even order the front-matching ones to the top.
To return the list to unfiltered state, press either the Enter key or Backspace key.
I like to type * on the Monticello list to see just my dirty packages.
- Chris