I like the new immediately accessible and immediately applied filter in IS.
But if you filter for something then close IS and then open IS, then filter field is still filled but not applied. I would classify it as a bug: it is misleading, and not very user friendly (if you want to search again with the same filter you have to e.g. delete and retype the last letter so that it applies again.)
IMO if IS frame gets opened with search filter filled, the search filter should get applied right away.
Also two more icing-on-the-cake points:
* if IS frame gets opened with search filter filled, it would be nice if cursor/focus were right away in the search-filter field (it would both draw attention to the fact that filter is appied, and allow modifying it right away)
* you could also add a little (x) to the right of the search field so that users could clear it with one click?
