I have my unit running with the prebuilt windows version.
I have it over clocked to 275mhz and the resulting hash rate reported by CGM is about 2.18ghs WU27.1/m.
I am seeing a high error rate (around 10%).
Strange thing is I seem to get this error rate no matter what clock rate I have tried.
What do you adjust in the settings?
I'm running with cgminer.exe --bmsc-options 115200:20 -o --
bmsc-freq 0781
The Github for Antminer has a guide with all the settings you could adjust for the U1. It was very helpful for me!