Coolie..., I concede that there are some BenQ1640s that have been rma'd, although I can't tell you where manuf'd and date. I saw one guy that had in his signature line that he had rma'd 3 and was waiting on his 4th. Possibly the best advice is to either buy from a reputable online merchant with an easy RMA/exchange policy, or a local store that would be the same way, both good rep. and easy exchange.
In today's world, there are fewer and fewer things one can guarantee, and certainly buying just b/c something is 'recommended' (but buying from anyone) doesn't guarantee you'll get a fully functional, problem-free unit. Sadly, all of us have to be more careful about where we buy and do as much research as possible on it pre-purchase. Just because of how 'profit-minded' so many companies are anymore, I'd say a 100% guarantee on getting something of 'true quality' is not reasonable and possibly hasn't been for at least a few years now.