PS Audio is about to come out with their next DAC and the man that designed both hardware and software has gone through pages of posts explaining in great detail the myriad of tradeoffs in design. The number of decisions made are staggering, but when they make a change, they then listen to the results. It isn't just having a buffer, but companies like Aurender have many years of iteration behind their present product. My iFi Zen Stream has a buffer, but it isn't an Aurender.