just that? i thought the humbuckers were different.
they are almost the same price, why does anyone buy the 520ex then?
The pickups are the same, its just that the S520EX has covered ones so they look more EMGish. EMGish=Metal. Claw inlay=Metal.
so to get a s520ex is just having less properties for the same price.
well the s520ex is really really black, and the s470dxqm isn't....depends on whether you prefer black guitars or not really

the s520ex is black or some other dark colour, has the same pickups minus the middle pup, has black hardware and has a cool inlay at the twelth

the s470dxqm is quilt top (some bright colour i assume), has the same pickups but has the middle pup, has silver hardware and has cool inlays all the way along

it's just a matter of taste i guess, some people find the middle pickup pointless as they might not use it much or some people just prefer they way one of them looks, it's all a matter of personal opinion basically