I bought a USB Bitmain AntMiner U1 a few days ago to mine Bitcoin and, today, I tested it both with cgminer as explained in the instructions from the company and with the latest version of bfgminer (3.10.0) at the stock frequency of 1.6 GH/s.
In the first case, I got up to 5% of HW errors but I don't see them in bfgminer.
The running frequency looks also more stable with bfgminer.
I uninstalled the driver before using bfgminer because cgminer requires the use of Zadig.
I use Windows (8.1) and if it doesn't work, you could also use "USBDeview" to uninstall the driver completely (
http://www.nirsoft.net/utils/usb_devices_view.html). I used USBDeview myself but I suppose my problem was more the Comodo firewall which requires a restart of Windows before really allowing the miner through after adding it in the allowed applications.
I would have to test and compare the number of rejected shares in both cases but it looks like bfgminer works better with the AntMiner U1, maybe due to the fact that it can use the driver as is without modifying it with Zadig.