Re: [ANN] US/North American Bitfury sales now open ***full prototype pics***
Productive night of troubleshooting... Thanks to everyone for all their pointers and advice in this thread.
Dayummm, that's sexy. I can get 520 Gh out of one, but I have a couple bad boards on the other and it can only get up to 422 Gh. 
In the interest of full disclosure, that number is not my Bitfury gear exclusively. Have one rig running near 520 more-or-less stable, and another rig with 3 bad h-cards (2 DOA and 1 with a malfunctioning pot that won't volt above 0.127V and hashes at <2GHs) is stable at near 400. Have an RMA pending for the 3 bad cards after doing extensive testing last night.
Will be doing more troubleshooting and tuning this weekend when I move the rigs out of their test environments.