My guess would be the high failure rate is because quite a few people change the faceplate and it requires exact mounting or the door won't close all the way. Most times this problem is hard to recognize. I have used a Liteon 167T and currently the AOpen and I will stick with the AOpen. Nothing wrong with the Liteon, just the Aopen is faster and better for errors. There is also an Toshiba that a lot of people swear by. Also I have seen quite a few comments about the reading abilities of the Benq 1620. Do a litle digging searching for 1648 AAP and you can probably find the dealer who has them in stock. I think it is Ajump.com.
You need exactly the 1648 AAP, not any other model. If it is too much trouble to get, the Liteon 167T is a good second choice, just get the 9S19 firmware from http://codeguys.rpc1.org/firmwares.html
If you want the ability to scan your burns, the 1620 Benq would be an alternative, but I have checked most of my 3500 burns and I have yet to see any problems. I only wind up with troubles on the Liteon I use to scan with, so I only burn on the NEC now.
I am not sure whether the 1620 has a riplock so check in the Benq forum to see what they say.
BTW, what media do you plan to use?