I don't like the artificial nature of mock trial competitions. The absence of a real jury, in my view, encourages advocacy tactics and gamesmanship that would never work in the real world and would in fact, be counterproductive. Students learn to do what looks and sounds great to other lawyers, but sometimes don't consider the impact of their choices on lay people. This is not necessarily so, by the way--I think some of the top teams I've seen would be amazing with a jury--but the artificial tactics are common enough to be a problem--especially with teams that are ethically and behaviorally challenged.
I've always wondered what it would be like in these competitions if we had lay juries and tried a case to verdict.