Lauren would have an ES which would be absolutely nothing like the actual 5820ks being shipped to people.
The last three launches Intel have pulled the old trick, send out loads of cherry picked chips.
Back in reality the 4770k was a terrible clocker, with some struggling to reach 4.2ghz, and that was only four cores.
As 8 pack has pointed out these are hot CPUs. Hotter than X79, which means clock speeds will be lower than X79.
You have to remember at all times that this is Haswell with more cores, more volts and more heat.
Edit. You also need to remember that the 5820k is highly likely to be the 5930ks that did not make the grade. It's easy for Intel to simply lock the lanes out of them...
It's kinda like the Pentium that just released. I've seen none go higher than 4.8ghz, yet you'd expect to easily sail past that given it's only two cores with no HT so heat would be at a minimum.