Trial without jury. Right or wrong?

For the first time in 350 years Britain had a trial without a jury. The case involved 4 men accused along with others of the £1.75m armed robbery, at the Menzies World Cargo warehouse at Heathrow in February 2004. Three previous trials collapsed due to a number of reasons, including alleged jury tampering. The prosecution, fearing the same might happen in the next trial, successfully appealed to the Court of Appeal to allow an unprecedented trial without a jury in England and Wales. The Appeal Court agreed there was a "real and present" danger of jury tampering, and considered that even a £6m package of protective measures by the police would not prevent it. Despite defence objections that they had not been provided with any evidence of jury interference, the first jury-less trial went ahead. Trial number four started in January 2010 at the Royal Courts of Justice with Mr Justice Treacy in charge.  

At the end of the trial Mr Justice Treacy did not give the usual summing up as there was no jury present to remind of the facts.
"The time has come for me to consider my verdicts and deliver a reasoned judgement," he simply said - and left court for an undisclosed period.
With no days lost due to jury sickness the whole trial had taken place in less than half the time of the previous trials - just three months rather than six.

But the costs of this series of trials is said to have risen to more than £20m. In the end Mr Justice Treacy found all four men guilty of the charges and would pass sentences later.

With jury tampering being a major problem with cases like this or for the more complicated fraud cases where jurors are expected to sit through months of legal and intricate submissions, surely trial without juries must be welcomed?

But could this set a precedent, whereby defendents could automatically be convicted of a crime? The legal right for trial by jury was a hard fought one and one which should not be given up lightly, but do we need to make exceptions with certain types of crime?