Well, maybe I just haven't played enough yet but my experience so far is that signature checks actually do reduce the amount of cheating. For example a few days ago I went from one server with no signature checks to another and so did at least one of the cheaters from the previous server and he was kicked right away, along with other people who had modified files. As for people who timed out I'd say there where 2 - 3 of them that I noticed during the time I was connected but that's far from 30% of the user base.
Now, I don't know if the signature checks have improved, if my experience is out of the ordinary, or if those particular cheaters where more lazy then the rest, but too me at least it seemed that the checks where actually doing some good.
