@taiganaut Just launch "Global Search" in #AndStatus for a #hashtag (or a !bangtag), and you will get a list of messages, which contain this tag, from all Social networks (to which your accounts belong).
Regarding slowness compared to web UI - this is due to these factors:
* Launching of a large application like Google Chrome definitely takes time.
* AndStatus stores data to a local database first, and then retrieves data from it for display. This could be optimized, of course...