Which is the best way to learn those operators. The shortcut "/" to get to the search box is probably what I use the most, and writing "from:john to:mailing-list" is such a great time saver, if you compare to other mail clients.
This is what makes Gmail very powerful for me.
I also use [ and ] a lot. From message view, they archive the current message and immediately move to the previous/next message in the current list.