I'd say if you're guilty, a jury trial gives you a better chance of getting off because of the random selection of jurors. I wasn't impressed by some of the people sharing the benches with me.
When I was called up, one fellow member of the jury had decided that one of the defendants was guilty because 'he gave me a dirty look'. I was just psyching up for my Henry Fonda impersonation when the judge threw out the case.