so to clarify, you're saying every device off the manufacturing line will be exactly the same as every other device, and every implementation of all the dac chips in the world are meaningless because of 1 chip in the pcb?
wow.
that's like saying the cpu with the fastest clock speed will do the work the quickest - ignoring physical topology, cache layers & sizes, ipc stages, etc.; if you look at a single number you miss the larger picture of how the system works.
do all cars that go 100mph drive the same?