The potential advantages over our broken status quo make this format worth trying:
Candidates will face the toughest questions. Who has the strongest incentive to ask Trump the hard questions? Clinton. And vice versa.
The debate will be transparently unbiased. Only a foolish and very sore loser would blame their opponent for asking tough questions.
Candidates can fact-check each other. The limited rebuttals of the current format will be replaced by a flexible format moderated by the clock to allow candidates to contest the other’s exaggerations.
The debate would move faster. The current format provides an incentive for candidates to bloviate for the entire allocated time, even wandering off topic. This format will encourage candidates to preserve time for later rebuttals.
The debate could go deeper. Now, candidates generally have to give brief answers even when the question is so important that it really requires more depth.