The company I work for has both the BenQ 1620 and the Nu Tech DDW-163. It's a long story about why we have both, short version is Nu Tech isn't doing desktop optical drives anymore and when we RMA'd some DDW-082 (8x DVD +/- RW) they sent us the DDW-163 drives for replacements.
Anyway, the Nu drive is the same as the BenQ and I have already flashed it to the retail firmware and the RPC-1 firmware from The Dangerous Brothers. 2 guys at work bought the drives since we are selling them cheaper than the BenQ drives since they are on our discontinued list and I flashed the drives for them. I have a BenQ 1620 which I purchased from work last December and flashed it to retail and RPC-1 firmware and it works beautifully.
Here is a link to The Dangerous Brothers home page, where the RPC-1 firmware is.
Get help from someone familiar with flashing optical drives if you don't know what you are doing. There is potential to permanently damage your drive.