John,
Generally the "something" tagged for newcomers to try out is the beta release. Until a release reaches beta status, it's not for use by the faint of heart, or those giving demos. If someone suggested using CVS HEAD for serious work, they were mistaken.
Besides, as someone who has given a few demos in her time I can assure you that even with packaged software from big-name companies it's always a good idea to run through your demo *before* you present anything to an audience, especially if that audience is predisposed to be skeptical. You never know what gremlins you may uncover, or just things that don't work quite the way you thought they would.
