I owned the 500 and can attest that it is a great transport. Very smooth and natural.
In terms of the difference between it and the 506....the 500 will have its own dedicated power supplied and circuitry not shared with the DA section. Although the physical CDM module may be the same, the other stuff around it can make a big difference.
In terms of the difference between it and the 506....the 500 will have its own dedicated power supplied and circuitry not shared with the DA section. Although the physical CDM module may be the same, the other stuff around it can make a big difference.