Last IIRC the biostarr will only run 1 stick of 1866, or if you do try to run it, the sticks will have to be in sockets 1 and 3, and you will have to play around some with memory interleaving.
easiest way to get it to work is to clock it down to 1600 and then bush the bclk up from there. Atleast that is what i have had to do.

I am working on a review aswell. I spent all of lastweek fighting with the biostar. Before I ordered the Asus f1a75-pro and the gigabyte ud4. Like you said the gigabyte seems to have the advantage right now. Though it does not support Multipliers past the chips set standard multi. The Asus will provide more voltage, but its allways high by .01 to .05volts, despite setting down the vrm controls. Which is the worst thing for these chips. The higher you have to crank the voltage on any of the Fusion chips the heat will increase more dramaticaly than on say a phenomII. I am guessing this is due to the IGP. The Asus board also currently lacks good IGP control.