Has anyone tried this case with fanxpert 2 and quiet components?
Is it quieter than Define r4?
I haven't used either case, but judging by the designs, the answer to your second question is probably, "Depends on your system." The R4 is likely to be quieter at lower flows because it blocks all direct noise paths, while the 540 is likely to gain the advantage as flow-rates increase because airflow is less restricted and more direct to hot components.
On the other hand, the 540 isn't going to hide much PSU noise, thanks to that vent on the side-panel.
Keep in mind, though, that this assumes you're not using the stock case fans and that both cases are well-constructed (ie, no rattly drive cages, etc), and that some SPCR-goers would argue that my reasoning is flawed and the 540's approach is just plain better