The four hour races are going to play havoc with stint lengths for the three driver teams unless minimum driving times rules don't apply.
And all that way to China for a four hour race? And eight hours in Bahrain that barely draws a crowd of three blokes and a camel!
I think they always wanted to move away from a fixed six hours for the non LM races, and the survey question was rigged to give the result the wanted from the fans if I remember rightly.
Still, with a four hour race at Silverstone, and no F3 next year it does give the chance to have a longer more relevant race added to the card. Endurance legends anyone?